顔写真

シミズ マコト
清水 信
Makoto Shimizu
所属
大学院工学研究科 機械機能創成専攻 エネルギー学講座(新エネルギー変換工学分野)
職名
准教授
学位
  • 博士(工学)(東北大学)

  • 修士(工学)(東北大学)

経歴 4

  • 2021年4月 ~ 継続中
    東北大学 工学研究科 機械機能創成専攻 准教授

  • 2013年4月 ~ 2021年3月
    東北大学大学院工学研究科 助教

  • 2015年4月 ~ 2016年3月
    INSA Lyon Visiting Scholar

  • 2011年4月 ~ 2013年3月
    日本学術振興会特別研究員DC2

学歴 3

  • 東北大学大学院 工学研究科 機械システムデザイン工学専攻博士後期課程3年の課程

    2010年4月 ~ 2013年3月

  • 東北大学大学院 工学研究科 機械システムデザイン工学専攻博士前期課程2年の課程

    2008年4月 ~ 2010年3月

  • 東北大学 工学部

    2004年4月 ~ 2008年3月

所属学協会 5

  • 電気学会

  • 応用物理学会

  • 日本機械学会

  • 日本太陽エネルギー学会

  • 日本伝熱学会

研究キーワード 5

  • レクテナ

  • 熱光起電力発電

  • 波長選択性材料

  • 太陽エネルギー

  • 熱ふく射

研究分野 3

  • ナノテク・材料 / 応用物理一般 /

  • ものづくり技術(機械・電気電子・化学工学) / 熱工学 /

  • ナノテク・材料 / エネルギー化学 /

受賞 6

  1. 文部科学大臣表彰 若手科学者賞

    2023年4月 文部科学省 熱輻射コヒーレンス制御に基く太陽エネルギー利用技術の研究

  2. 第25回青葉工学研究奨励賞

    2019年12月 一般財団法人 青葉工学振興会 熱光起電力発電を用いた太陽エネルギー高度利用技術の実現

  3. 優秀論文発表賞

    2017年4月 一般社団法人電気学会

  4. 日本太陽エネルギー学会奨励賞(学生部門)

    2013年5月 日本太陽エネルギー学会

  5. 大学院研究奨励賞

    2010年3月 公益社団法人自動車技術会

  6. 日本機械学会三浦賞

    2010年3月 日本機械学会

︎全件表示 ︎最初の5件までを表示

論文 46

  1. Enhanced current density and asymmetry of metal-insulator-metal diodes based on self-assembly of Pt nanoparticles 査読有り

    Zhen Liu, Shunsuke Abe, Makoto Shimizu, Hiroo Yugami

    Applied Physics Letters 122 (9) 2023年2月27日

    DOI: 10.1063/5.0123591  

    ISSN:0003-6951

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    Metal-insulator-metal (MIM) diodes facilitate rectification at high frequencies. However, the rectification ratio for light from visible to infrared spectra is insufficient. In this study, we developed a MIM diode with a strongly enhanced electric field achieved using the self-assembly of Pt nanoparticles (NPs) via atomic layer deposition. By shaping the tunneling barrier, current density and asymmetry were simultaneously enhanced by several orders of magnitude compared with the symmetric MIM diode. The diode efficiency of the proposed MIM diodes was experimentally demonstrated to be 231 times greater than that of the MIM diode without NPs. This strategy indicates significant potential for high-frequency rectification applicable in optical rectenna.

  2. Highly confined spectrally selective absorber-emitter for effective solar thermophotovoltaics 査読有り

    Makoto Shimizu, Tomoya Furuhashi, Zhen Liu, Hiroo Yugami

    Solar Energy Materials and Solar Cells 245 111878-111878 2022年9月

    出版者・発行元:Elsevier BV

    DOI: 10.1016/j.solmat.2022.111878  

    ISSN:0927-0248

  3. Advances in thermophotovoltaics: Materials, devices, and systems

    Alejandro Datas, Mathieu Francoeur, Makoto Shimizu, Rodolphe Vaillon

    Solar Energy Materials and Solar Cells 240 2022年6月15日

    DOI: 10.1016/j.solmat.2022.111711  

    ISSN:0927-0248

  4. Optical rectenna with wide wavelength coverage from a hollow resonator coupled with a metal-insulator-metal tunnel diode 査読有り

    Daisuke Matsuura, Makoto Shimizu, Zhen Liu, Hiroo Yugami

    Applied Physics Express 15 (6) 2022年6月

    DOI: 10.35848/1882-0786/ac6c1b  

    ISSN:1882-0778

    eISSN:1882-0786

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    This study proposes an optical rectenna that combines a hollow resonator with a metal-insulator-metal (MIM) tunnel diode that is capable of photoelectric conversion (at various visible and infrared wavelengths). It enables the conversion of thermal radiation with different peak wavelengths, such as sunlight and thermal radiation (from heat sources in various temperature ranges), into electric power. The MIM tunnel diode was placed on the wall of a hollow resonator. It rectified the induced current generated by the resonance of the magnetic field. The photoelectric conversion capability of the proposed device applied to visible light is experimentally demonstrated in this study.

  5. Emission bandwidth control on a two-dimensional superlattice microcavity array 査読有り

    Zhen Liu, Makoto Shimizu, Hiroo Yugami

    Optics Express 30 (8) 13839-13846 2022年4月

    DOI: 10.1364/OE.455722  

    eISSN:1094-4087

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    Narrowband thermal emission at high temperatures is required for various thermal energy systems. However, the large lossy energy of refractory metals induces a broad bandwidth emission. Here, we demonstrated a two-dimensional (2D) superlattice microcavity array on refractory metals to control the emission bandwidth. A hybrid resonance mode was obtained by coupling the standing-wave modes and propagating surface-wave modes. The bandwidth emission was controlled by varying the superlattice microcavity array resulting from the change in electric field (E-field) concentration. The quality factor (Q-factor) improved by more than 3 times compared to that of a single-lattice array. A narrower band emission originating from the hybrid mode was observed and analyzed experimentally. This novel surface-relief microstructure method can be used to control the emission bandwidth of thermal emitters used in thermophotovoltaic (TPV) systems and other high-temperature thermal energy systems.

  6. Multiband infrared emissions limited in the grazing angle from metal-dielectric-metal metamaterials 査読有り

    Rihab Benlyas, Makoto Shimizu, Keiya Otomo, Zhen Liu, Hiroo Yugami

    Optics Express 30 (6) 9380-9388 2022年3月14日

    DOI: 10.1364/OE.450802  

    eISSN:1094-4087

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    Thermal radiation management remains a challenge because of the incoherent and isotropic nature of electromagnetic waves. In this study, a multiband and angular-selective infrared emitter, consisting of a simple one-dimensional (1D) metal-dielectric-metal metamaterial, is demonstrated. Although this structure has been well known as spectrally selective emitters, we analytically reveal that when the dielectric layer thickness is much smaller than the wavelength of interest (< 1/10), directive emission at nearly equal to the grazing angles (> 80°) can be obtained at multiple resonant wavelengths. As the absorption peaks can be entirely characterized by geometrical parameters, this angular selective technology offers flexible control of thermal radiation and can be adjusted to specific applications.

  7. Effective photon recycling in solar thermophotovoltaics using a confined cuboid emitter 査読有り

    Asaka Kohiyama, Makoto Shimizu, Kana Konno, Tomoya Furuhashi, Hiroo Yugami

    Optics Express 28 (26) 38567-38567 2020年12月7日

    出版者・発行元:The Optical Society

    DOI: 10.1364/oe.412764  

    eISSN:1094-4087

  8. Amorphous Nanohole Patterns Formed by Spinodal Decomposition of Nickel Superalloys for Solar-Selective Absorbers 査読有り

    Makoto Shimizu, Zhen Liu, Hiroo Yugami

    ACS Applied Nano Materials 3 (9) 9502-9509 2020年9月25日

    DOI: 10.1021/acsanm.0c02238  

    eISSN:2574-0970

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    Copyright © 2020 American Chemical Society. Materials with tailored spectral absorptance properties are essential for the effective photothermal conversion of sunlight. This study demonstrates that solar-selective absorption properties can be achieved by the disordered amorphous pattern structures formed by the spinodal decomposition of a nickel superalloy, in contrast to many other techniques of tailoring spectral properties by employing ordered structures such as photonic crystals. The study reveals that short-range ordered structures can be obtained via spinodal decomposition by controlling the annealing conditions. Short-range ordered nanostructures are crucial to achieving high absorptance over a broad range in the solar spectrum and low emittance in the thermal radiation range from the absorber because of the Anderson localization effect. Corresponding to the spectrally selective absorption, the advantages of blackbody-like absorption are demonstrated by analyzing the performance factor of photothermal conversion. Using the spinodal decomposition process, it is possible to fabricate these structures on large-scale areas and nonplanar surfaces. Therefore, this technology is expected to increase the efficiency of various solar thermal energy systems.

  9. Quantitative evaluation of optical properties for defective 2D metamaterials based on diffraction imaging 査読有り

    Zhen Liu, Makoto Shimizu, Hiroo Yugami

    Optics Express 28 (4) 5812-5821 2020年2月17日

    DOI: 10.1364/OE.385100  

    eISSN:1094-4087

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    © 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement Metamaterials are intriguing candidates for energy conversion systems, and contribute to the control of thermal radiation spectra. Large-scale devices are required to provide high energy flux transfer. However, the surface microstructure of large-scale metamaterials suffers from fabrication defects, inducing optical property degradation. We develop a novel approach to quantitatively evaluate the optical properties of defective 2D metamaterials based on diffraction imaging. The surrogate surface structure is reconstructed from diffraction pattern, and analyzed geometrical features to evaluate the optical properties. This approach shows potential for in-line and real-time continuous diagnosis during industrial fabrication, and high-throughput for large-scale 2D metamaterial.

  10. High-current density and high-asymmetry MIIM diode based on oxygen-non-stoichiometry controlled homointerface structure for optical rectenna 査読有り

    Daisuke Matsuura, Makoto Shimizu, Hiroo Yugami

    SCIENTIFIC REPORTS 9 2019年12月

    出版者・発行元:NATURE PUBLISHING GROUP

    DOI: 10.1038/s41598-019-55898-x  

    ISSN:2045-2322

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    Optical rectennas are expected to be applied as power sources for energy harvesting because they can convert a wide range of electromagnetic waves, from visible light to infrared. The critical element in these systems is a diode, which can respond to the changes in electrical polarity in the optical frequency. By considering trade-off relationship between current density and asymmetry of IV characteristic, we reveal the efficiency limitations of MIM diodes for the optical rectenna and suggest a novel tunnel diode using a double insulator with an oxygen-non-stoichiometry controlled homointerface structure (MOx/MOx-y). A double-insulator diode composed of Pt/TiO2/TiO1.4/Ti, in which a natural oxide layer of TiO1.4 is formed by annealing under atmosphere. The diode has as high-current-density of 4.6 x 10(6) A/m(2), which is 400 times higher than the theoretical one obtained using Pt/TiO2/Ti MIM diodes. In addition, a high-asymmetry of 7.3 is realized simultaneously. These are expected to increase the optical rectenna efficiency by more than 1,000 times, compared to the state-of-the art system. Further, by optimizing the thickness of the double insulator layer, it is demonstrated that this diode can attain a current density of 10(8) A/m(2) and asymmetry of 9.0, which are expected to increase the optical rectenna efficiency by 10,000.

  11. Evaluation of thermal stability in spectrally selective few-layer metallo-dielectric structures for solar thermophotovoltaics 査読有り

    Makoto Shimizu, Asaka Kohiyama, Hiroo Yugami

    Journal of Quantitative Spectroscopy and Radiative Transfer 212 45-49 2018年6月

    DOI: 10.1016/j.jqsrt.2018.02.037  

  12. Radiative heat transfer enhancement using geometric and spectral control for achieving high-efficiency solar-thermophotovoltaic systems 査読有り

    Asaka Kohiyama, Makoto Shimizu, Hiroo Yugami

    Japanese Journal of Applied Physics 57 (4) 2018年4月1日

    出版者・発行元:Japan Society of Applied Physics

    DOI: 10.7567/JJAP.57.040312  

    ISSN:1347-4065 0021-4922

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    We numerically investigate radiative heat transfer enhancement using spectral and geometric control of the absorber/emitter. A high extraction of the radiative heat transfer from the emitter as well as minimization of the optical losses from the absorber leads to high extraction and solar thermophotovoltaic (STPV) system efficiency. The important points for high-efficiency STPV design are discussed for the low and high area ratio of the absorber/emitter. The obtained general guideline will support the design of various types of STPV systems.

  13. Spectrally shaping high-temperature radiators for thermophotovoltaics using Mo-HfO2 trilayer-on-substrate structures 査読有り

    Etienne Blandre, Makoto Shimizu, Asaka Kohiyama, Hiroo Yugami, Pierre-Olivier Chapuis, Rodolphe Vaillon

    Optics Express 26 (4) 4346-4357 2018年2月19日

    出版者・発行元:OSA - The Optical Society

    DOI: 10.1364/OE.26.004346  

    ISSN:1094-4087

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    Easy-to-fabricate, high-temperature, thermally-stable radiators are critical elements for developing e cient and sustainable thermophotovoltaic energy conversion devices. In this frame, a trilayer-on-substrate structure is selected. It is composed of a refractory metal - molybdenum - constituting the substrate and an intermediate thin film sandwiched between two hafnia transparent layers. An in-depth analysis shows that two spectrally distinct interference regimes take place in the hafnia layer-molybdenum thin film substructure, and that backward and forward thermally-emitted waves by the thin film are selected in two distinct interferential resonating cavities. The interference regimes within and between these cavities are key to the spectral shaping of thermal emission. The radiative performances of the structures are evaluated by introducing a figure of merit. Using the example of a GaSb cell, it is shown that the structure can be optimized for providing the broadband large emission with a steep cuto required for mitigating photoconversion losses.

  14. Development of small power sources based on a micro-SOFC system operated on liquid fuels for mobile electric devices 査読有り

    S. Takahara, K. Kato, F. Iguchi, M. Shimizu, H. Yugami

    ECS Transactions 78 (1) 1871-1878 2017年5月30日

    出版者・発行元:Electrochemical Society Inc.

    DOI: 10.1149/07801.1871ecst  

    ISSN:1938-6737 1938-5862

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    A small power source was designed based on a liquid hydrocarbon fueled micro-SOFC. In order to achieve thermal insulation in a restricted volume, a vacuum thermal insulator was developed and tested it revealed that even a 1 mm vacuum zone showed high thermal resistivity over 200 KW-1 at 300°C. Internal reforming tests with methanol-based fuels were performed with an isolated micro reformer the results suggested that sufficient amount of methanol could be reformed at 400°C. Finally, an integrated system of thermal insulator, reformer, and micro-SOFC was tested to prove the feasibility of the design, which was expected to achieve higher energy density per volume/mass than Li-ion batteries.

  15. High spectral selectivity for solar absorbers using a monolayer transparent conductive oxide coated on a metal substrate 査読有り

    Makoto Shimizu, Mari Suzuki, Fumitada Iguchi, Hiroo Yugami

    JOURNAL OF APPLIED PHYSICS 121 (18) 2017年5月

    出版者・発行元:AMER INST PHYSICS

    DOI: 10.1063/1.4983189  

    ISSN:0021-8979

    eISSN:1089-7550

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    A spectrally selective absorber composed of a monolayer transparent conductive oxide (TCO) coated on a metal substrate is investigated for use in solar systems operating at temperatures higher (&gt;973K) than the operation temperature of conventional systems (similar to 673 K). This method is different from the currently used solar-selective coating technologies, such as those using multilayered and cermet materials. The spectral selective absorption property can be attributed to the inherent optical property of TCO owing to the plasma frequency and interferences between the substrates. Since spectral selectivity can be achieved using monolayered materials, the effect of atomic diffusion occurring at each layer boundary in a multilayer or cermet coatings under hightemperature conditions can be reduced. In addition, since this property is attributed to the inherent property of TCO, the precise control of the layer thickness can be omitted if the layer is sufficiently thick (&gt;0.5 mu m). The optimum TCO properties, namely, carrier density and mobility, required for solar-selective absorbers are analyzed to determine the cutoff wavelength and emittance in the infrared range. A solar absorptance of 0.95 and hemispherical emittance of 0.10 at 973K are needed for achieving the optimum TCO properties, i.e., a carrier density of 5.5 x 10(20) cm(-3) and mobility of 90 cm(2) V-1 s(-1) are required. Optical simulations indicate that the spectrally selective absorption weakly depends on the incident angle and film thickness. The thermal stability of the fabricated absorber treated at temperatures up to 973K for 10 h is verified in vacuum by introducing a SiO2 interlayer, which plays an important role as a diffusion barrier. Published by AIP Publishing.

  16. Application of in-situ Raman scattering spectroscopy for stress condition measurement in solid oxide fuel cells 査読有り

    Fumitada Iguchi, Shoma Onuki, Makoto Shimizu, Tatsuya Kawada, Hiroo Yugami

    JOURNAL OF THE CERAMIC SOCIETY OF JAPAN 125 (4) 213-217 2017年4月

    出版者・発行元:CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI

    DOI: 10.2109/jcersj2.16275  

    ISSN:1882-0743

    eISSN:1348-6535

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    A feasible study for an in-situ stress evaluation method for solid oxide fuel cells based on Raman scattering spectroscopy was performed using two anode-supported cells with a cathode interlayer made from Samarium (Sm) doped ceria. Model cells with a dense cathode interlayer demonstrated a compressive stress of -100s MPa at room temperature, and the results were comparable to those from X-ray diffraction. Model cells with a porous interlayer showed complex stress conditions that deviated from in-plane stress due to their porosity, and the model cell was confirmed not to be suitable for this method. At high temperatures, compressive stress was found to decrease as temperature increased and was almost neutral at the operating temperatures of the fuel cell, with good replication. Hence, the feasibility of this method for model cells with a dense cathode interlayer was confirmed. (C) 2017 The Ceramic Society of Japan. All rights reserved.

  17. Enhanced thermal transport in polymers with an infrared-selective thermal emitter for electronics cooling 査読有り

    Shinichiro Tsuda, Makoto Shimizu, Fumitada Iguchi, Hiroo Yugami

    APPLIED THERMAL ENGINEERING 113 112-119 2017年2月

    出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD

    DOI: 10.1016/j.applthermaleng.2016.11.024  

    ISSN:1359-4311

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    Passive thermal management has attracted much attention for use in electronic devices. In this study, we propose a novel thermal management technique based on spectral matching between thermal radiation and the infrared optical window of polymers, which are widely used in device encapsulation and packaging. The unique effects of this technique on heat transfer were numerically and experimentally studied. Our numerical analysis confirms that selectively enhancing thermal radiation in the optical window of polymers improved thermal propagation deep into the polymers, reducing local temperature distributions at their surface. In addition, our experiments demonstrate that boosting thermal radiation propagation deep into polymers effectively enhanced their heat spreading and dissipation. Our new method for thermal management in polymers can improve passive thermal management in electronic devices that include polymers. (C) 2016 Elsevier Ltd. All rights reserved.

  18. 多層膜被覆周期的微細構造を用いた高温用太陽光選択吸収材料 査読有り

    清水信, 阿久津宏樹, 津田慎一郎, 引地広介, 熊野勝文, 湯上浩雄

    電気学会論文誌E部門誌 137 (11) 393-399 2017年

    出版者・発行元:None

    DOI: 10.1541/ieejsmas.137.393  

    ISSN:1347-5525 1341-8939

  19. High-temperature Solar Selective Absorbers Based on a Transparent Conductive Oxide Film Coated Periodic Micro-hole Array 査読有り

    Makoto Shimizu, Toshiro Abe, Fumitada Iguchi, Hiroo Yugami

    INTERNATIONAL CONFERENCE ON CONCENTRATING SOLAR POWER AND CHEMICAL ENERGY SYSTEMS (SOLARPACES 2016) 1850 2017年

    出版者・発行元:AMER INST PHYSICS

    DOI: 10.1063/1.4984494  

    ISSN:0094-243X

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    A transparent conductive oxide (TCO) film coated metal microstructures as solar selective absorbers for high-temperature usage exceeding 700 degrees C is introduced. Steep absorption cutoff property and low-emittance at infrared range owing to TCO characteristic can be seen, whereas high-absorptance explained by interaction of incident light and microstructures of which size is submicron is appeared. Honeycomb array cylindrical microcavity of which an absorptance peak appeared at around 0.8 mu m was fabricated on a tungsten (W) surface with interference lithography technique. The fabricated sample consist of 1.0 mu m indium tin oxide film and W microstructure showed solar absorptance alpha(s) = 0.83, hemispherical emittance epsilon(ht)= 0.16 assuming the absorber temperature at 700 degrees C, and performance factor eta = 0.76. Short duration thermal stability was confirmed at 700 degrees C for 2 h in vacuum condition.

  20. Multilayer coated microstructure for solar selective absorbers 査読有り

    Makoto Shimizu, Hiroki Akutsu, Shinichiro Tsuda, Kosuke Hikichi, Masafumi Kumano, Hiroo Yugami

    IEEJ Transactions on Sensors and Micromachines 137 (11) 393-399 2017年

    出版者・発行元:Institute of Electrical Engineers of Japan

    DOI: 10.1541/ieejsmas.137.393  

    ISSN:1347-5525 1341-8939

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    Solar selective absorbers that function at temperatures up to 700°C and possess shallow honeycomb cylindrical microcavities coated with a metal-dielectric multi-layer are investigated. Even shallow microcavities, absorptance at solar spectrum range is largely increased due to multilayer showing spectrally selective absorption property. To obtain high spectral selective property, design strategy for the multilayer coated microstructure is established. Honeycomb array cylindrical microcavities were fabricated on tungsten substrate and multi-layers consisting of platinum nano-film sandwiched by aluminum oxide layers were created for a uniform coating via atomic layer deposition. Thermal stability of the fabricated sample at 700oC in vacuum is verified through annealing test for 100 h.

  21. Unidirectional radiative heat transfer with a spectrally selective planar absorber/emitter for high-efficiency solar thermophotovoltaic systems 査読有り

    Asaka Kohiyama, Makoto Shimizu, Hiroo Yugami

    APPLIED PHYSICS EXPRESS 9 (11) 2016年11月

    出版者・発行元:IOP PUBLISHING LTD

    DOI: 10.7567/APEX.9.112302  

    ISSN:1882-0778

    eISSN:1882-0786

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    A high-efficiency solar thermophotovoltaic (STPV) system has been demonstrated using spectrally selective planar absorber/emitter systems and a GaSb TPV cell. In this study, a novel approach for designing the STPV system based on the efficiency of unidirectional radiative heat transfer has been introduced. To achieve high extraction and photovoltaic conversion efficiencies, the spectrally selective absorber/emitter based on a coherent perfect absorber composed of a thin molybdenum layer sandwiched between hafnium layers was applied. The extraction efficiency was further investigated with respect to the absorber/emitter area ratio. The experimental efficiency of STPV reached 5.1% with the area ratio of 2.3. (C) 2016 The Japan Society of Applied Physics

  22. A high-temperature solar selective absorber based upon periodic shallow microstructures coated by multi-layers using atomic layer deposition 査読有り

    Makoto Shimizu, Hiroki Akutsu, Shinichiro Tsuda, Fumitada Iguchi, Hiroo Yugami

    Photonics 3 (2) 13 2016年6月1日

    出版者・発行元:MDPI AG

    DOI: 10.3390/photonics3020013  

    ISSN:2304-6732

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    Regarding the fabrication of solar selective absorbers, the ability to create microstructures on top of metal surfaces is a promising technology. Typically, these materials are able to possess spectrally-selective absorption properties for high-temperature usage. Solar-selective absorbers that function at temperatures up to 700 °C and possess shallow honeycomb cylindrical microcavities coated with a metal-dielectric multi-layer have been investigated. Honeycomb array cylindrical microcavities were fabricated on W substrate with interference lithography and multi-layers consisting of Pt nano-film sandwiched by Al2O3 layers were created for a uniform coating via atomic layer deposition. The absorbance spectrum of fabricated samples reveals results consistent with a simulation based on a rigorous coupled-wave analysis method. A solar absorbance value of 0.92 and a hemispherical total emittance value of 0.18 at 700 °C was determined from the fabricated solar-selective absorber. Additionally, thermal stability of up to 700 °C was confirmed in vacuum.

  23. 高ふく射繊維を用いた高温炉におけるエネルギー回収 査読有り

    小島匠, 酒井淳, 清水信, 井口史匡, 湯上浩雄, 井口浩詠, 久行輝美, 中川成人, 山村武民

    日本機械学会論文集 82 (838) 1500588-1-1500588-12 2016年

    DOI: 10.1299/transjsme.15-00588  

  24. Development of methanol fueled micro-SOFC system for mobile electronic devices

    S. Takahara, K. Kato, F. Iguchi, M. Shimizu, H. Yugami

    ECS Transactions 75 (42) 33-41 2016年

    出版者・発行元:Electrochemical Society Inc.

    DOI: 10.1149/07542.0033ecst  

    ISSN:1938-5862 1938-6737

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    Feasible study of whole micro-SOFC system using methanol fuel for small power sources in mobile electronic devices was performed. These new power sources are required to achieve heat-self-sustainability and thermal consistency due to its high operating temperature. To satisfy the requirements, energy flow in the system consists of insulation packages stored micro-SOFC was calculated based on thermodynamics, and achievement was evaluated by changing the thickness of insulator. Calculation results confirmed that the requirements were satisfied with small size packages, could be stored in mobile electronic devices. In addition, volumetric energy density of the system was higher than that of Li-ion batteries. Therefore, it was confirmed that the application of micro-SOFC as a new power sources for mobile electronic devices had advantage compared to Li-ion batteries.

  25. Narrowband thermal radiation from closed-end microcavities 査読有り

    Asaka Kohiyama, Makoto Shimizu, Fumitada Iguchi, Hiroo Yugami

    Journal of Applied Physics 118 (13) 2015年10月7日

    出版者・発行元:American Institute of Physics Inc.

    DOI: 10.1063/1.4931375  

    ISSN:1089-7550 0021-8979

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    High spectral selectivity of thermal radiation is important for achieving high-efficiency energy systems. In this study, intense, narrowband, and low directional absorption/radiation were observed in closed-end microcavity which is a conventional open-end microcavity covered by a semi-transparent thin metal film. The quality factor (Q factor) of optical absorption band strongly depended on the film electrical conductivity. Asymmetric and narrow absorption band with a Q factor of 25 at 1.28 μm was obtained for a 6-nm-thick Au film. Numerical simulations suggest that the formation of a fixed-end mode at the cavity aperture contributes to the narrowband optical absorption. The closed-end microcavity filled with SiO2 exhibits intense and isotropic thermal radiation over a wide solid angle according to numerical simulation. The narrow and asymmetric absorption spectrum was experimentally confirmed in a model of closed-end microcavity.

  26. Thermal Management Technique Using Control of Thermal Radiation Spectrum for Encapsulated Electronic Devices 査読有り

    Shinichiro Tsuda, Makoto Shimizu, Fumitada Iguchi, Hiroo Yugami

    IEEE TRANSACTIONS ON COMPONENTS PACKAGING AND MANUFACTURING TECHNOLOGY 5 (7) 971-979 2015年7月

    出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

    DOI: 10.1109/TCPMT.2015.2443914  

    ISSN:2156-3950

    eISSN:2156-3985

    詳細を見る 詳細を閉じる

    The role of thermal management has been critical in the design of electronic devices. This issue is especially important in handheld electronic devices. Here, we investigate a new thermal management technique that controls thermal radiation spectrum using a 2-D periodic microstructure. In this technique, heat generated from an electronic device in the form of thermal radiation directly enters the ambient environment without absorption by external packages such as resin. In this paper, radiative heat transfer in the encapsulated-electronic-device model is experimentally evaluated to clearly show the effect of the proposed technique. This effectiveness of the technique for reducing the temperature of electronic devices and external packages is demonstrated. Moreover, the cooling effect of the technique is clearly observed as the contribution of the radiative heat transfer is increased. This paper suggests that thermal radiation is effective for thermal management of electronic devices in small spaces.

  27. Anisotropic multi-step etching for large-area fabrication of surface microstructures on stainless steel to control thermal radiation 査読有り

    M. Shimizu, T. Yamada, K. Sasaki, A. Takada, H. Nomura, F. Iguchi, H. Yugami

    SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 16 (2) 2015年4月

    出版者・発行元:IOP PUBLISHING LTD

    DOI: 10.1088/1468-6996/16/2/025001  

    ISSN:1468-6996

    eISSN:1878-5514

    詳細を見る 詳細を閉じる

    Controlling the thermal radiation spectra of materials is one of the promising ways to advance energy system efficiency. It is well known that the thermal radiation spectrum can be controlled through the introduction of periodic surface microstructures. Herein, a method for the large-area fabrication of periodic microstructures based on multi-step wet etching is described. The method consists of three main steps, i.e., resist mask fabrication via photolithography, electrochemical wet etching, and side wall protection. Using this method, high-aspect micro-holes (0.82 aspect ratio) arrayed with hexagonal symmetry were fabricated on a stainless steel substrate. The conventional wet etching process method typically provides an aspect ratio of 0.3. The optical absorption peak attributed to the fabricated micro-hole array appeared at 0.8 mu m, and the peak absorbance exceeded 0.8 for the micro-holes with a 0.82 aspect ratio. While argon plasma etching in a vacuum chamber was used in the present study for the formation of the protective layer, atmospheric plasma etching should be possible and will expand the applicability of this new method for the large-area fabrication of high-aspect materials.

  28. Influence of small defects produced in electrolytes during manufacturing processes on operated SOFCs

    S. Onuki, F. Iguchi, M. Shimizu, T. Kawada, H. Yugami

    ECS Transactions 68 (1) 2421-2428 2015年

    出版者・発行元:Electrochemical Society Inc.

    DOI: 10.1149/06801.2421ecst  

    ISSN:1938-6737 1938-5862

    詳細を見る 詳細を閉じる

    The influence of gas leakage through penetrated holes introduced during fabrication was experimentally evaluated using in-situ Raman scattering spectroscopy. Gas chromatography analysis of pressure differences between the anode and the cathode revealed that the gas leakage through the holes was dominated by gas diffusion through the anode, and that the pressure difference did not influence the amount of gas leakage. In-situ measurements in an operated cell with a hole revealed combustion between leaked H2 and air occurred around the hole, the O&lt inf&gt 2&lt /inf&gt partial pressure at this hole was not sufficiently low to reduce NiO, and the temperature increased by almost 10°C around the hole. In contrast, no influence on stress distributions was observed.

  29. Design of new power source based on micro-SOFC for mobile electronic devices

    S. Murayama, F. Iguchi, M. Shimizu, S. Tanaka, H. Yugami

    ECS Transactions 68 (1) 2349-2355 2015年

    出版者・発行元:Electrochemical Society Inc.

    DOI: 10.1149/06801.2349ecst  

    ISSN:1938-6737 1938-5862

    詳細を見る 詳細を閉じる

    A package consisting of a vacuum insulator and a heat exchanger was designed to enable power sources based on micro-SOFCs fueled by liquid fuels thermally sustainable and consistent with other electronics in mobile electronic devices. Gas-liquid heat exchanger worked for cooling the edge of the thermal insulator and recovering the latent and sensible heat of exhaust gases. Numerical analysis using a finite element method and experiment using a prototype package revealed that using liquid fuels based on methanol could reduce the surface temperature of the package to lower than 85°C at the operation temperature lower than 500°C, and thermally sustainable operation could be achieved by heat recovery at this range.

  30. High-efficiency solar-thermophotovoltaic system equipped with a monolithic planar selective absorber/emitter 査読有り

    Makoto Shimizu, Asaka Kohiyama, Hiroo Yugami

    JOURNAL OF PHOTONICS FOR ENERGY 5 2015年1月

    出版者・発行元:SPIE-SOC PHOTO-OPTICAL INSTRUMENTATION ENGINEERS

    DOI: 10.1117/1.JPE.5.053099  

    ISSN:1947-7988

    詳細を見る 詳細を閉じる

    We demonstrate a high-efficiency solar-thermophotovoltaic system (STPV) using a monolithic, planar, and spectrally selective absorber/emitter. A complete STPV system using gallium antimonide (GaSb) cells was designed and fabricated to conduct power generation tests. To produce a high-efficiency STPV, it is important to match the thermal radiation spectrum with the sensitive region of the GaSb cells. Therefore, to reach high temperatures with low incident power, a planar absorber/emitter is incorporated for controlling the thermal radiation spectrum. This multilayer coating consists of thin-film tungsten sandwiched by yttria-stabilized zirconia. The system efficiency is estimated to be 16% when accounting for the optical properties of the fabricated absorber/emitter. Power generation tests using a high-concentration solar simulator show that the absorber/emitter temperature peaks at 1640 K with an incident power density of 45 W/cm(2), which can be easily obtained by low-cost optics such as Fresnel lenses. The conversion efficiency became 23%, exceeding the Shockley-Queisser limit for GaSb, with a bandgap of 0.67 eV. Furthermore, a total system efficiency of 8% was obtained with the view factor between the emitter and the cell assumed to be 1. (C) 2015 Society of Photo-Optical Instrumentation Engineers (SPIE)

  31. Residual stress in NiO-YSZ composites and its relationship to microstructure

    Y. Akaza, T. Syu, F. Iguchi, M. Shimizu, H. Yugami

    ECS Transactions 68 (1) 1291-1296 2015年

    出版者・発行元:Electrochemical Society Inc.

    DOI: 10.1149/06801.1291ecst  

    ISSN:1938-6737 1938-5862

    詳細を見る 詳細を閉じる

    Residual stress in NiO-YSZ was numerically simulated using 2D models consisting of the arrays of NiO and YSZ particles to evaluate the influence of thermal stress due to the large difference of thermal expansion coefficient between NiO and YSZ. The influence of geometric microstructure changed by fabrication processes was also evaluated using the models with different arrangements. Numerical simulation revealed that thermal strains introduced from the hetero-interfaces canceled each other, and residual stress in a uniform model was small. But, in non-uniform model, residual stress increased because counterpart stress was absent at homo-interfaces due to non-uniformity. Simulation results also indicated that a part of particles near the interfaces was exposed to high residual stress as a reaction to thermal stress.

  32. Application of high-temperature photonics for solar energy systems 査読有り

    Makoto Shimizu, Asaka Kohiyama, Hiroaki Kobayashi, Mari Suzuki, Fumitada Iguchi, Hiroo Yugami

    Proceedings of NanoRad2014 36-37 2014年6月6日

  33. HIGH-TEMPERATURE PHOTONICS FOR ADVANCED SOLAR ENERGY APPLICATIONS

    Makoto Shimizu, Asaka Kohiyama, Fumitada Iguchi, Hiroo Yugami

    Proceedings of Grand Renewable Energy 2014 2014年

  34. 10% efficiency solar thermophotovoltaic systems using spectrally controlled monolithic planar absorber/emitters 査読有り

    Makoto Shimizu, Asaka Kohiyama, Hiroo Yugami

    PHOTONICS FOR SOLAR ENERGY SYSTEMS V 9140 91400P 2014年

    出版者・発行元:SPIE-INT SOC OPTICAL ENGINEERING

    DOI: 10.1117/12.2057315  

    ISSN:0277-786X

    詳細を見る 詳細を閉じる

    In solar thermophotovoltaic (STPV) generation systems, the thermal radiation from emitters heated by the high temperature solar absorbers is converted into electricity at a photovoltaic (PV) cell. STPV systems have some advantages over PV generation systems. For instance, it is possible to control the thermal radiation spectrum of the emitter. Generally, the PV cell has an inherent sensitive region where an incident photon excites the electron. Enhancing the thermal radiation in this sensitive region of the PV cell, therefore, increases the generation efficiency. Theoretically, the efficiency of STPV systems can reach up to 85% when Carnot efficiency is considered and up to 45% when a monochromatic radiation releasing emitter is used. However, the experimental STPV system is less efficient than theoretical one as a consequence of the large amount of heat loss from the high-temperature absorber/emitter system. The purpose of this study is to achieve a high-efficiency STPV generation system using a monolithic planar spectrally selective absorber/emitter. The temperature superiority of the monolithic planar absorber/emitter is estimated by using spectral and thermal properties of STPV system components. Using the enitre configuration of the STPV system, a system efficiency of over 10% is estimated in this study.

  35. High-temperature photonics using self-organization of superalloys for solar selective absorbers

    Makoto Shimizu, Kiyotaka Konno, Hiroaki Kobayashi, Fumitada Iguchi, Hiroo Yugami

    2013 ISES SOLAR WORLD CONGRESS 57 411-417 2014年

    出版者・発行元:ELSEVIER SCIENCE BV

    DOI: 10.1016/j.egypro.2014.10.194  

    ISSN:1876-6102

    詳細を見る 詳細を閉じる

    Making surface microstructures on refractory metal is one of the promising technologies of controlling optical property at high-temperature condition. However, the technique of fabricating microstructures for refractory metal is limited, such as using semiconductor technologies. Therefore, the large-area fabrication of periodic microstructures on refractory metals is a key technology supporting the practical application of controlling optical property using surface microstructures. This report describes large-area fabrication of two-dimensional submicron quasi-periodic microcavities using self-organization on a nickel-based superalloy. The surface microcavities on a bulk metal were obtained by appropriate heat treatments and simple chemical etching process. The spectrally selective property attributed to the confined modes inside cavities is observed. The selective absorbing property and thermal stability are also confirmed at 973 K. Therefore, this fabrication method can be applied for high temperature solar selective absorbers. The fabricated sample showed solar absorptance of 0.74 and emittance of 0.25 at 873 K. The performance of solar selective absorber is verified by simple heating test using the sample with randomly arrayed microstructures. It is indicated that the temperature of microstructured sample shows 30 degrees C higher than that of a black-painted sample. (C) 2014 The Authors. Published by Elsevier Ltd.

  36. Spectrally Controlled Thermal Radiation Based on Surface Microstructures for High-Efficiency Solar Thermophotovoltaic system

    Asaka Kohiyama, Makoto Shimizu, Hiroaki Kobayashi, Fumitada Iguchi, Hiroo Yugami

    2013 ISES SOLAR WORLD CONGRESS 57 517-523 2014年

    出版者・発行元:ELSEVIER SCIENCE BV

    DOI: 10.1016/j.egypro.2014.10.205  

    ISSN:1876-6102

    詳細を見る 詳細を閉じる

    Thermophotovoltaic (TPV) system is expected to generate electrical power from various heat sources. One of the key devices of TPV system is spectrally control thermal emitters. The performance is not sufficient to achieve high efficient TPV systems. In this study, we developed new t,,pe spectral selective emitters with closed-end surface microcavit,, array. The simulated spectral thermal radiation band width is only 70nm and Q-value=26.4. This Q-value is 5 times larger than the conventional open-end microcavity emitters. The design of Solar-TPV system which is driven by concentrated solar energy using refractory metal emitters with multilayer coating. The estimated system efficiency and electric power density using the experimentally obtained spectral property of the selective emitters is 16.6% and 2.9W/cm(2), respectively. (C) 2014 Published by Elsevier Ltd.

  37. High-temperature solar selective absorbers using transparent conductive oxide coated metal

    Makoto Shimizu, Mari Suzuki, Fumitada Iguchi, Hiroo Yugami

    2013 ISES SOLAR WORLD CONGRESS 57 418-426 2014年

    出版者・発行元:ELSEVIER SCIENCE BV

    DOI: 10.1016/j.egypro.2014.10.195  

    ISSN:1876-6102

    詳細を見る 詳細を閉じる

    In these days, the application of using thermal energy of sunlight has become widely used in concentrated solar power generation systems (CSP). In CSP, property of the receiver directly contributes to the system efficiency of CSP. The solar selective absorber is used for the receiver to reduce energy loss of thermal radiation. To investigate the mass production technology of fabricating solar selective absorber that can be utilized in high temperature condition, we focused on transparent conductive oxides (TCO) thin film on metal substrate. TCO material has plasma wavelength in infrared region. Therefore the electromagnetic wave with shorter wavelength than plasma wavelength goes through the material, while the electromagnetic wave with longer wavelength is reflected on the surface. It is realized that TCO on metal substrate showed high performance as solar selective absorbers, i.e. high absorptance in visible light range and low emittance in infrared range by numerical simulations. The optical property of fabricated TCO coated metal is well consistent with the simulated property. Consequently, we attain high performance solar selective absorber of which solar absorptance is 0.71 and hemispherical total emittance is 0.11. The thermal stability is also confirmed at 600 degrees C in vacuum for 3 hr. (C) 2014 The Authors. Published by Elsevier Ltd.

  38. 高温フォトニクス材料を用いた熱光起電力発電システム

    湯上浩雄, 清水信

    応用物理学会誌 82 (11) 946-949 2013年11月

    出版者・発行元:応用物理学会

    ISSN:0369-8009

  39. Design and Fabrication of Micro SOFC for the Power Source of Mobile Electric Devices

    S. Murayama, F. Iguchi, Y. Inagaki, M. Shimizu, S. Tanaka, H. Yugami

    SOLID OXIDE FUEL CELLS 13 (SOFC-XIII) 57 (1) 799-806 2013年

    出版者・発行元:ELECTROCHEMICAL SOC INC

    DOI: 10.1149/05701.0799ecst  

    ISSN:1938-5862

    詳細を見る 詳細を閉じる

    A package for the power source of mobile electronic devices based on micro solid oxide fuel cells (micro-SOFCs) was designed considering thermal management. The package should suppress its surface temperature lower than harmless value for other electrical circuits, and thermal consistency should be kept. In addition, other functions such as gas flow and electrical connection were installed into the package. Hence, high performance thermal insulation structure with good machinability was necessary. We applied thermal insulation structure made of Si wafers and glasses by MEMS technologies. The convection heat transfer was prevented by the structure equipped with a vacuum zone. Experimental and theoretical consideration revealed that the purpose could be achieved at apparent thermal conductivity of the structure lower than 0.02 W/ mK. In accordance with the consideration, a package was designed, and its thermal insulation performances were evaluated.

  40. Evaluation of Stress Condition of Operated Anode Supported-Type SOFC under Operating Conditions Based on Raman Scattering Spectroscopy

    S. Onuki, S. Onodera, F. Iguchi, M. Shimizu, T. Kawada, H. Yugami

    SOLID OXIDE FUEL CELLS 13 (SOFC-XIII) 57 (1) 951-957 2013年

    出版者・発行元:ELECTROCHEMICAL SOC INC

    DOI: 10.1149/05701.0951ecst  

    ISSN:1938-5862

    詳細を見る 詳細を閉じる

    Stress in an anode-supported type solid oxide fuel cell (SOFC) was measured by in-situ measurement using micro Raman scattering spectroscopy. The stress conditions evaluation method focuses on Raman spectra of samarium-doped ceria (SDC) which was used as an interlayer in SOFC. The shift of ceria Raman peak and peak width in SDC interlayer were measured to evaluate stress, temperature, and Sm concentration. We performed this method in the purchased cells of conventional anode-supported type SOFC under thermal cycles, which simulate start-up and shout down. Observed results suggested that not only thermal stress relaxation but also diffusion of samarium from an interlayer to an electrolyte, and stress relaxation by plastically deformation were occurred.

  41. Stress Conditions Transition by Thermal Annealing in Barium Zirconate Based Proton Conducting Thin Films Fabricated Using PLD Method

    T. Fukushige, F. Iguchi, M. Shimizu, H. Yugami

    SOLID OXIDE FUEL CELLS 13 (SOFC-XIII) 57 (1) 1045-1051 2013年

    出版者・発行元:ELECTROCHEMICAL SOC INC

    DOI: 10.1149/05701.1045ecst  

    ISSN:1938-5862

    詳細を見る 詳細を閉じる

    Barium zirconate based proton conducting thin films were fabricated using PLD method with ArF Excimer laser under high and low oxygen partial pressures on silicon wafers, and stress conditions and its transition by thermal annealing were measured by XRD side inclination method. Stress conditions were changed by thermal annealing, and two stress transition modes were observed. Stress condition in the films deposited at high oxygen partial pressure was compressive and the value was changed to tensile by thermal annealing. Considering the difference of thermal expansion coefficient, stress condition due to thermal stress was tensile. Therefore, this transition was defined as stress relaxation. By contrast, the films deposited at low oxygen partial pressure showed tensile stress condition, and transited to compressive stress condition, i.e. stress increment. These two modes were probably due to the transition of intrinsic stress caused by surface energy, which was sensitive to the deposition atmospheres.

  42. Relationship between Electrical Properties and Stress Field in Solid Electrolyte Thin Films

    Y. Osawa, F. Iguchi, M. Shimizu, H. Yugami

    SOLID OXIDE FUEL CELLS 13 (SOFC-XIII) 57 (1) 1097-1102 2013年

    出版者・発行元:ELECTROCHEMICAL SOC INC

    DOI: 10.1149/05701.1097ecst  

    ISSN:1938-5862

    詳細を見る 詳細を閉じる

    Stress in yttria stabilized zirconia (YSZ) thin films was controlled by using various substrates, which had different thermal expansion coefficient (TEC), and electrical properties of the films were measured to study the relationship between the stress filed and electrical properties. Thin films of YSZ were deposited by PLD method on Al2O3 and AlN substrates. Because TEC of YSZ is larger than that of the substrates, tensile stress field was introduced into the films at room temperature. Measured stress value by XRD was varied from 0.7 to 1.7 GPa at R. T. This value is significantly higher than literature value. However, the films also showed different lattice volume on the different substrates. Although electrical properties in the films showed different tendencies by the substrates, both stress field and lattice volume were different. Hence, stress dependence of electrical properties was not clearly observed.

  43. Fabrication of quasi-periodic surface microcavities by selective etching of self-organized superalloys for high-temperature photonics 査読有り

    Makoto Shimizu, Kiyotaka Konno, Fumitada Iguchi, Hiroo Yugami

    APPLIED PHYSICS LETTERS 101 (22) 2012年11月

    出版者・発行元:AMER INST PHYSICS

    DOI: 10.1063/1.4767903  

    ISSN:0003-6951

    詳細を見る 詳細を閉じる

    Large-area fabrication of periodic microstructures on refractory metals surface is a key technology supporting the practical application of spectrally controlled thermal radiation using surface microcavities. This report describes large-area fabrication of two-dimensional submicron quasi-periodic microcavities using self-organization on a nickel-based superalloy. The surface microcavities on a bulk metal are obtained by heat treatment and simple chemical etching. The emission peak attributed to the confined modes inside cavities can be tuned by controlling the microcavity size from 0.27 to 0.53 mu m. Emittance enhancement and thermal stability are also confirmed at 973 K. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4767903]

  44. Application Technologies of Spectrally Controlled Thermal Radiation Using Microstructures for Energy Systems 査読有り

    Makoto Shimizu, Fumitada Iguchi, Hiroo Yugami

    Proceedings of international workshop on Nano - Micro thermal radiation 92-95 2012年6月

  45. Thermal Radiation Control by Surface Gratings as an Advanced Cooling System for Electronic Devices 査読有り

    Makoto Shimizu, Hiroo Yugami

    JOURNAL OF THERMAL SCIENCE AND TECHNOLOGY 6 (2) 297-306 2011年

    出版者・発行元:JAPAN SOC MECHANICAL ENGINEERS

    DOI: 10.1299/jtst.6.297  

    ISSN:1880-5566

    詳細を見る 詳細を閉じる

    Recently, the spectral properties of thermal radiation have been controlled by surface gratings having a size in the optical wavelength range, and this technique has been applied to improve the efficiency of energy systems, e.g., thermophotovoltaic generators and sky radiators. In this paper, the technique was applied to an advanced cooling system for electronic devices. In general, electronic devices are packaged in resin to protect them from damage; however, resin prevents heat from escaping from the package because of resin's strong absorption of thermal radiation in the infrared range and low thermal conductivity. By controlling the spectral property of thermal radiation from electronic devices, the thermal radiation absorbed by resin can be decreased. As a result, a cooling system for electronic devices is possible. At first, we performed a numerical simulation to design the optimal surface gratings to cool electronic devices packaged in epoxy resin. The surface gratings were fabricated using a MEMS process. The performance of the fabricated emitter was evaluated experimentally. In conclusion, we confirmed that this new cooling technique will be effective for electronic devices.

  46. J0103-4-2 波長選択性熱放射による樹脂パッケージされた電子デバイスの冷却促進(電子情報機器,電子デバイスの強度・信頼性評価と熱制御(4))

    清水 信, 湯上 浩雄

    年次大会講演論文集 2009 71-72 2009年

    出版者・発行元:一般社団法人日本機械学会

    DOI: 10.1299/jsmemecjo.2009.6.0_71  

    詳細を見る 詳細を閉じる

    This paper describes the new technique of cooling electronic devices packaged in resin. In recent years, cooling electronic devices becomes very serious problem. To enhance thermal radiation from electronic devices, this problem is improved because 20%-40% of heat is dissipated by radiative heat transfer. We report new technique about cooling electronic devices to control radiative spectra from its surface. Resin which packages an electronic device prevents radiation from going outside air. We consider that radiation from electronic devices transmits resin to control radiative spectra. As a result, cooling performance improved. A spectral selective emitter which consists of periodical micron meter scale two-dimensional grating on metal surface can control radiative spectra. In this research, we decide an optimal selective emitter design from simulation and fabricated it by micro-machining technology. Finally, the fact that using spectral selective emitter enhanced cooling performance is obtained from cooling performance test.

︎全件表示 ︎最初の5件までを表示

MISC 36

  1. 金属ナノ薄膜を用いた微小共振器構造からの低指向性準単色熱放射

    清水信, 矢部雄斗, 小桧山朝華, 井口史匡, 湯上浩雄

    応用物理学会秋季学術講演会講演予稿集(CD-ROM) 79th ROMBUNNO.20a‐225B‐5 2018年9月5日

  2. 太陽熱光起電力発電システムにおけるふく射抽出効率の向上

    小桧山朝華, 小桧山朝華, 清水信, 湯上浩雄

    応用物理学会春季学術講演会講演予稿集(CD-ROM) 65th ROMBUNNO.19a‐C301‐4 2018年3月5日

  3. Fabrication of surface microstructures based on spinodal decomposition for high-temperature solar selective absorbers

    Makoto Shimizu, Toshiro Abe, Fumitada Iguchi, Hiroo Yugami

    International Heat Transfer Conference 2018-August 7689-7694 2018年1月1日

    ISSN:2377-424X

    詳細を見る 詳細を閉じる

    © 2018 International Heat Transfer Conference. All rights reserved. Making periodically aligned microstructures with sub-micron size on a refractory metal is one of the promising technologies of increasing solar absorption selectively at high-temperature condition. However, the technique of fabricating microstructures for refractory metal is limited, such as using semiconductor technologies. Therefore, the large-area fabrication of microstructures on refractory metals is a key technology supporting the practical application of controlling optical property using surface microstructures. This report describes large-area fabrication of two-dimensional submicron quasi-periodic microstructures using spinodal decomposition on a nickel-based superalloy. The surface microstructures were obtained only by appropriate heat treatments and simple chemical etching process. The size of microstructure; i.e. depth, width, can be controlled with heat treatment conditions and etching time. Solar selective absorptance of 0.82 and hemispherical total emittance of 0.31 at 600oC can be obtained with the proper treatments.

  4. 集光太陽光を用いた熱光起電力発電システムの発電試験

    小桧山朝華, 清水信, 湯上浩雄

    太陽/風力エネルギー講演論文集 2017 235‐238 2017年10月25日

  5. ふく射熱輸送特性と波長選択性の太陽熱光起電力発電システム効率への影響(II)

    小桧山朝華, 小桧山朝華, 清水信, 湯上浩雄

    応用物理学会秋季学術講演会講演予稿集(CD-ROM) 78th ROMBUNNO.5p‐PB2‐1 2017年8月25日

  6. 熱ふく射スペクトル制御に基づく高効率な太陽熱光起電力発電システムの開発

    清水信, 小桧山朝華, 湯上浩雄

    クリーンエネルギー 26 (4) 7‐12-12 2017年4月10日

    出版者・発行元:日本工業出版

    ISSN:0918-7510

  7. ふく射熱輸送特性と波長選択性の太陽熱光起電力発電システム効率への影響

    小桧山朝華, 清水信, 湯上浩雄

    応用物理学会春季学術講演会講演予稿集(CD-ROM) 64th ROMBUNNO.17a‐514‐2 2017年3月1日

  8. 金属ナノ薄膜-透明誘電体膜積層構造による熱ふく射スペクトル制御 (フィジカルセンサ マイクロマシン・センサシステム 合同研究会 メタマテリアル・プラズモニック構造を基軸とする新機能創成)

    清水 信, 小桧山 朝華, 湯上 浩雄

    電気学会研究会資料. PHS 2016 (58) 39-42 2016年12月19日

    出版者・発行元:電気学会

  9. 多層膜積層型微細構造による太陽光選択吸収材料

    清水 信, 阿久津 宏樹, 津田 慎一郎, 熊野 勝文, 湯上 浩雄

    「センサ・マイクロマシンと応用システム」シンポジウム論文集 電気学会センサ・マイクロマシン部門 [編] 33 1-6 2016年10月2日

    出版者・発行元:Institute of Electrical Engineers of Japan

  10. 熱輸送効率向上による太陽熱光起電力発電システムの高効率化

    小桧山朝華, 清水信, 湯上浩雄

    応用物理学会秋季学術講演会講演予稿集(CD-ROM) 77th ROMBUNNO.15p‐B4‐12 2016年9月1日

  11. 187 熱ふく射スペクトル制御を用いた樹脂パッケージされた電子デバイスからの放熱促進

    津田 慎一郎, 清水 信, 井口 史匡, 湯上 浩雄

    講演論文集 2016 (51) 171-172 2016年

    出版者・発行元:一般社団法人日本機械学会

  12. A solar thermophotovoltaic system using spectrally controlled monolithic planar thermal emitter/absorber

    Hiroo Yugami, Asaka Kohiyama, Makoto Shimizu, Fumitada Iguchi

    ASME 2016 5th International Conference on Micro/Nanoscale Heat and Mass Transfer, MNHMT 2016 1 2016年1月1日

    DOI: 10.1115/MNHMT2016-6692  

    詳細を見る 詳細を閉じる

    © 2016 by ASME. Solar-thermophotovoltaic system is expected to have high efficiency by converting wide spectral range solar energy into useful thermal radiation energy. However, the experimental STPV system shows much lower efficiency than theoretical one. To achieve high-efficiency, it is essential to obtain good spectrally matching between thermal radiation spectrum and PV cells spectral response. In this paper, the power generation tests using the whole configuration of the STPV system is described. The conversion efficiency of GaSb PV cell is estimated to be 20 to 23% against to the light intensity irradiated on the PV cell surface. The net system efficiency of 1.9% can be achieved. The application of thermal storage system to the STPV is also considered.

  13. Spectral control of thermal radiation using metal-dielectric multilayers for high-temperature usage over 1000°C

    Makoto Shimizu, Asaka Kohiyama, Fumitada Iguchi, Hiroo Yugami

    ASME 2016 5th International Conference on Micro/Nanoscale Heat and Mass Transfer, MNHMT 2016 1 2016年1月1日

    DOI: 10.1115/MNHMT2016-6699  

    詳細を見る 詳細を閉じる

    © 2016 by ASME. The spectrally selective coating technology which can be applicable for solar-thermophotovoltaic (solar-TPV) generation systems is described in this paper. In solar-TPV system, the spectrally selective absorber plays a key role to obtain highefficiency. The technologies of controlling thermal radiation spectrum at temperature over 1000oC, however, have not been established yet. We focus on metal-dielectric multi-layer coating. This selective coating shows enormously high absorptance at short wavelength range and sharp cutoff property. Thermal stability test confirms that this multi-layer structure can be one of the candidates for the selective coatings for solar-TPV systems.

  14. Solar-thermophotovoltaic systems using spectrally selective absorber/emitter based on metal-dielectric multilayer

    A. Kohiyama, M. Shimizu, H. Yugami

    Proceedings of SPIE - The International Society for Optical Engineering 9937 2016年1月1日

    DOI: 10.1117/12.2237672  

    ISSN:0277-786X

    詳細を見る 詳細を閉じる

    © 2016 SPIE. In this paper, high-efficiency STPV systems are investigated using spectrally selective absorber/emitter consisted of metal-dielectric multilayer and a GaSb TPV cell. A solar-thermophotovoltaic (STPV) system is expected to as highefficiency solar energy conversion using single-junction photovoltaic (PV) cells. However, the reached experimental system efficiency has been still low because spectral control of emitter is not sufficient. Narrowband thermal radiation from the emitter is effective for obtaining high-efficiency STPV systems, exceeding the Shockley-Queisser limit. From theoretical analysis, the narrowband thermal emitter can leads to obtain PV conversion efficiency over 45% at Qvalue= 30 and 1300K. The spectrally selective absorber/emitter was also investigated to obtain high ηPV. The ηPV = 23.5% was estimated by the fabricated emitter spectrum, which exceeds the Shockley-Queisser limit of 19.6% for a GaSb bandgap of 0.67 eV. The entire STPV system and the power generation tests were conducted using the fabricated absorber/emitter. The total system efficiency 4.9% at 1505K was obtained under an irradiance of 109 Wcm-2.

  15. Low-directivity quasi-monochromatic thermal radiation from microcavities covered by thin metal film

    Asaka Kohiyama, Makoto Shimizu, Fumitada Iguchi, Hiroo Yugami

    ASME 2016 5th International Conference on Micro/Nanoscale Heat and Mass Transfer, MNHMT 2016 1 2016年1月1日

    DOI: 10.1115/MNHMT2016-6683  

    詳細を見る 詳細を閉じる

    © 2016 by ASME. Here, closed-end microcavity is proposed in which a semi-transparent metal film was formed atop microcavity. The structure shows weak angular dependence as well as quasimonochromatic absorptance. Au is employed as material of the cavity walls and the covering thin film. Quasi-monochromatic absorption from the structure is observed in numerical simulation. High quality factor (Q factor) is obtained by strong confinement in the closed-end microcavity. Asymmetric and quasi-monochromatic absorption band with a Q factor of ∼28 at 1.85 μm was observed. This value was about 4-fold larger than that of the open-end microcavity. Additionally, the closed-end microcavity structure filled with SiO2in cavity exhibits isotropic and quasi-monochromatic thermal radiation over a wide solid angle. This result suggests that both quasimonochromatic and low-directivity absorptance can be realized by using this configuration.

  16. 熱ふく射スペクトル制御技術を用いた太陽熱光起電力発電システム

    小桧山朝華, 清水信, 井口史匡, 湯上浩雄

    応用物理学会秋季学術講演会講演予稿集(CD-ROM) 76th ROMBUNNO.15P-2C-15 2015年8月31日

  17. マイクロキャビティ構造に基づいた熱ふく射スペクトル準単色化

    小桧山朝華, 清水信, 井口史匡, 湯上浩雄

    電気学会マイクロマシン・センサシステム研究会資料 MSS-15 (15-34) 97-99 2015年7月3日

  18. 熱放射スペクトル制御材料を用いた高効率ソーラー熱光起電力発電

    清水信, 小桧山朝華, 酒井淳, 柳澤邦彦, 井口史匡, 湯上浩雄

    応用物理学会春季学術講演会講演予稿集(CD-ROM) 62nd ROMBUNNO.11A-P1-12 2015年2月26日

  19. マイクロキャビティ構造からの波長選択性熱ふく射スペクトル狭帯域化

    小桧山朝華, 清水信, 井口史匡, 湯上浩雄

    応用物理学会春季学術講演会講演予稿集(CD-ROM) 62nd ROMBUNNO.13P-A10-6 2015年2月26日

  20. ソーラー熱光起電力発電における熱放射スペクトル制御材料の高温特性

    清水信, 柳沢邦彦, 小桧山朝華, 井口史匡, 湯上浩雄

    応用物理学会秋季学術講演会講演予稿集(CD-ROM) 75th ROMBUNNO.19A-A23-3 2014年9月1日

  21. OS1613 面内圧縮応力状態下における安定化ジルコニアの電気的特性

    井口 史匡, 山根 拓也, 清水 信, 湯上 浩雄

    M&M材料力学カンファレンス 2014 "OS1613-1"-"OS1613-2" 2014年7月19日

    出版者・発行元:一般社団法人日本機械学会

    詳細を見る 詳細を閉じる

    Lattice volume of solid state ionic conductors was closely related to its electrical properties, because oxygen ion, proton and other ionic carriers migrate via hopping between sights in lattice. Therefore, in the case of conventional developing of ionic conductors, i.e. doping different valent element, lattice volume change caused by doping had been discussed. In this study, we attempted the effect of outer forces to lattice volume and its influence to electrical properties. Yttrium stabilized zirconia was adopted to be objective materials, because it is most popular electrolyte material for SOFCs. Single crystalline pellets of YSZ were fitted into the basement made of Al_2O_3 and Si_3N_4 at room temperature, and annealed. Compressive outer forces was applied in axial directions because thermal expansion coefficient is differ between YSZ (10.3×10^<-6> K^<-1>), Al_2O_3 (7.7×10^<-6> K^<-1>) and Si_3N_4 (3.2×10^<-6> K^<-1>). The applied forces reached to 800 MPa at 800 oC with the Si_3N_4 basement. Electrical conductivity of YSZ pellets was measured in vertical direction to stress plane, and the influence of lattice modulation was discussed.

  22. 高温フォトニクスによるふく射熱輸送の高効率化

    清水信, 小桧山朝華, 井口史匡, 湯上浩雄

    電気学会マイクロマシン・センサシステム研究会資料 MSS-14 (1-4.6-23) 109-112 2014年5月27日

  23. 135 高ふく射性SiC系繊維を用いた高温炉におけるエネルギー回収

    小島 匠, 酒井 淳, 清水 信, 井口 史匡, 湯上 浩雄

    講演論文集 2014 (49) 71-72 2014年

    出版者・発行元:一般社団法人日本機械学会

  24. Application of transparent conductive oxides films for high-temperature solar selective absorbers

    Makoto Shimizu, Mari Suzuki, Asaka Kohiyama, Fumitada Iguchi, Hiroo Yugami

    ASME 2014 8th International Conference on Energy Sustainability, ES 2014 Collocated with the ASME 2014 12th International Conference on Fuel Cell Science, Engineering and Technology 1 2014年1月1日

    DOI: 10.1115/ES2014-6353  

    詳細を見る 詳細を閉じる

    Copyright © 2014 by ASME. At present, the utilization of thermal energy from sunlight has been widely adopted as the working principle of concentrated solar power (CSP) generation systems. In this research, we suggest a CSP technology based on the properties of transparent conductive oxide (TCO) films on metal substrates which is compatible with mass production of solar selective absorbers that can be utilized at high temperatures. TCO material has plasma wavelength in infrared region. Therefore the electromagnetic wave with shorter wavelength than plasma wavelength goes through the material, while the electromagnetic wave with longer wavelength is reflected on the surface. By coating metal surface with a TCO film, interference is occurred in transparent wavelength range of TCO. Therefore, solar energy is highly absorbed, though thermal radiation from the absorber is suppressed. The optical property of fabricated TCO coated metal is well consistent with the simulated property. It is revealed that the performance of the absorber is improved by fabricating microstructures on the metal substrate. Thermal stability is confirmed at 700°C in vacuum for 3 hours. Solar absorptance and hemispherical emittance of the fabricated absorber are 0.82 and 0.17, respectively, which is comparable to that of commercialized absorbers.

  25. High-efficiency thermophotovoltaic system by quasi-monochromatic thermal radiation

    Asaka Kohiyama, Makoto Shimizu, Hiroaki Kobayashi, Fumitada Iguchi, Hiroo Yugami

    ASME 2014 8th International Conference on Energy Sustainability, ES 2014 Collocated with the ASME 2014 12th International Conference on Fuel Cell Science, Engineering and Technology 1 2014年1月1日

    DOI: 10.1115/ES2014-6743  

    詳細を見る 詳細を閉じる

    Copyright © 2014 by ASME. Efficiency of solar-thermophotovoltaic (TPV) systems can be improved by controlling spectral property of thermal radiation to match the photovoltaic (PV) cells spectral response. We developed a spectrally selective emitter which can emit quasi-monochromatic thermal radiation to improve the efficiency of TPV systems. From the evaluation by the detailed-balance model for gallium antimonite (GaSb) TPV cells, the photovoltaic conversion efficiency over 50 % is achievable in the case of the emitter temperature over 1800K and emitter Q-value over 15. The numerical simulation based on Rigorous-Coupled Wave Analysis revealed that the quasi-monochromatic thermal radiation can be obtained by closed-end microcavity structure. A solar-TPV system equipped with a solar-simulator is fabricated to evaluate the effect of spectrally selective emitter. By using GaSb TPV cells and spectrally selective emitter based on dielectric layer coating, photovoltaic conversion efficiency of 26% and total efficiency of 7.7% are obtained at emitter temperature of 1654 K under 384 suns.

  26. Thermal management of power sources for mobile electronic devices based on micro-SOFC

    S. Murayama, F. Iguchi, M. Shimizu, H. Yugami

    Journal of Physics: Conference Series 557 2014年1月1日

    DOI: 10.1088/1742-6596/557/1/012050  

    ISSN:1742-6588

    詳細を見る 詳細を閉じる

    © Published under licence by IOP Publishing Ltd. Small power sources based on micro-SOFC for mobile electronic devices required two conditions, i,e, thermally compatibility and thermally self-sustain, because of high operating temperature over 300oC. Moreover, high energy efficiency was also required. It meant that this system should be designed considering thermal management. In this study, we developed micro-SOFC packages which have three functions, thermal insulation, thermal recovery, and self-heating. Heat conduction analysis based on finite element method, and thermochemical calculation revealed that vacuum thermal insulation was effective for size reduction and gas-liquid heat exchanger could reduce the temperature of outer surface. We fabricated the package with three functions for proof of concept and evaluated. As a result, it was suggested that developed package could satisfy both two requirements with high efficiency.

  27. A solar thermophotovoltaic generation with a monolithic planar absorber/emitter material

    Hiroaki Kobayashi, Jun Sakai, Asaka Kohiyama, Makoto Shimizu, Fumitada Iguchi, Hiroo Yugami

    Optics InfoBase Conference Papers 2013年12月1日

    詳細を見る 詳細を閉じる

    A planar absorber/emitter in solar thermophotovoltaic system reaches high temperature with a small concentration ratio because of low thermal radiation loss. Using this planar absorber/emitter, the net efficiency is estimated to be 21%. Renewable Energy and the Environment Congress © 2013.

  28. 集光太陽光を用いた熱光起電力発電における太陽光選択吸収材料

    清水 信, 小桧山 朝華, 小林 大晃

    太陽/風力エネルギー講演論文集 73-76 2013年

    出版者・発行元:日本太陽エネルギー学会

  29. Practicable fabrication technology of high-temperature photonic materials for thermophotovoltaic systems

    Makoto Shimizu, Hiroaki Kobayashi, Kunihiko Yanagisawa, Fumitada Iguchi, Hiroo Yugami

    Optics InfoBase Conference Papers 2013年1月1日

    詳細を見る 詳細を閉じる

    The high-temperature photonic materials fabricated by practicable technology is described. The high-temperature photonic material using self-organization of a super-alloys and a monolithic planer absorber/emitter with multi-layer coating is obtained. Renewable Energy and the Environment Congress © 2013.

  30. 244 波長選択性太陽光吸収材料としての周期的微細構造を持つ耐熱性合金の作製(動力エネルギーシステム,一般講演)

    今野 晴天, 清水 信, 井口 史匡, 湯上 浩雄

    講演論文集 2012 (47) 294-295 2012年3月13日

    出版者・発行元:一般社団法人日本機械学会

  31. 透明導電酸化物の太陽光選択吸収材料への応用

    清水 信, 今野 晴天, 井口 史匡

    太陽/風力エネルギー講演論文集 327-330 2012年

    出版者・発行元:日本太陽エネルギー学会

  32. 周期的微細構造を持つ耐熱性合金を用いた太陽光選択吸収材料の作製

    今野 晴天, 清水 信, 井口 史匡

    太陽/風力エネルギー講演論文集 331-334 2012年

    出版者・発行元:日本太陽エネルギー学会

  33. High-temperature solar selective absorbers based on interface effects in refractory metals coated with transparent conductive oxides

    Makoto Shimizu, Fumitada Iguchi, Hiroo Yugami

    ASME 2012 6th International Conference on Energy Sustainability, ES 2012, Collocated with the ASME 2012 10th International Conference on Fuel Cell Science, Engineering and Technology 423-428 2012年1月1日

    DOI: 10.1115/ES2012-91256  

    詳細を見る 詳細を閉じる

    At present, the utilization of thermal energy from sunlight has been widely adopted as the working principle of concentrated solar power (CSP) generation systems. In this research, we suggest a CSP technology based on the properties of transparent conductive oxide (TCO) thin films on metal substrates which is compatible with mass production of solar selective absorbers that can be utilized at high temperatures. Since the plasma wavelength of TCO materials is in the infrared region, electromagnetic waves with wavelengths longer than the plasma wavelength are reflected at the surface, whereas electromagnetic waves with shorter wavelengths pass through the surface layer and reach the substrate. In other words, a TCO thin film behaves as an antireflection film only in the transparency range of TCO coating. This phenomenon is demonstrated through numerical simulations based on rigorous coupled-wave analysis (RCWA). The prepared samples also show favorable spectral selectivity and satisfactory performance as solar selective absorbers, with a solar absorptance of 0.76, a thermal emittance of 0.12 at 800°C and a spectral selectivity of 6.5 at 800°C. Copyright © 2012 by ASME.

  34. High-temperature solar selective absorber material using surface microcavity structures

    Makoto Shimizu, Kimio Takeuchi, Hitoshi Sai, Fumitada Iguchi, Noriko Sata, Hiroo Yugami

    ASME 2011 5th International Conference on Energy Sustainability, ES 2011 783-787 2011年12月1日

    DOI: 10.1115/ES2011-54599  

    詳細を見る 詳細を閉じる

    The spectral properties of thermal radiation can be controlled by surface microstructures with feature size in the optical wavelength range. We applied this technology to solar selective absorbers for concentrated solar power (CSP) generation systems. We investigated the spectral properties and thermal stability of two-dimensional periodic microstructures on a tungsten (W) surface to develop solar selective absorbers for high-temperature applications. The developed absorbers exhibited good spectral selectivity and sufficient thermal stability under vacuum. Although we could verified that the microstructured solar selective absorbers improved CSP efficiency, this method cannot be put into practical use because of cost and time, and also because there is currently no technology for fabricating surface gratings on high melting point materials over a large area. Therefore, we used W-Cu alloys to investigate an approach to mass production of surface microcavity structures over a large area. We then confirmed that the absorptivity in the visible light range could be increased by using this simple method. Copyright © 2011 by ASME.

  35. 150 表面微細構造による熱放射制御を用いた電子デバイス冷却への応用(熱工学,一般講演)

    清水 信, 湯上 浩雄

    講演論文集 2011 (46) 104-105 2011年3月15日

    出版者・発行元:一般社団法人日本機械学会

  36. 123 電子デバイス冷却への波長選択性熱放射の適用(学生賞IV,一般講演)

    清水 信, 湯上 浩雄

    講演論文集 2010 (45) 48-49 2010年3月12日

    出版者・発行元:一般社団法人日本機械学会

︎全件表示 ︎最初の5件までを表示

書籍等出版物 4

  1. 次世代の太陽電池・太陽光発電―その発電効率向上,用途と市場の可能性―

    清水 信

    技術情報協会 2018年4月

  2. 熱ふく射スペクトル制御に基づく高効率な太陽熱光起電力発電システムの開発

    清水 信, 小桧山 朝華, 湯上 浩雄

    クリーンエネルギー、26(4) 2017年

  3. ナローギャップPVセルを用いた熱光起電力発電

    湯上 浩雄, 清水 信

    応用電子物性分科会誌、24(2) 2015年

  4. 高温フォトニクス材料を用いた熱光起電力発電システム

    湯上 浩雄, 清水 信

    応用物理、82(11) 2013年

講演・口頭発表等 103

  1. 熱輻射制御による熱光起電力発電および熱放射スペクトル制御による電子デバイス冷却 招待有り

    湯上浩雄, 清水信

    CSJ化学フェスタ2020 2020年10月21日

  2. 光レクテナのための酸素不定比性制御に基づくホモ界面MIIMダイオードの作製

    清水信, 松浦大輔, 湯上浩雄

    第81回応用物理学会秋季学術講演会 2020年9月8日

  3. Microstructure-based spectral shaping of thermal radiation for high-temperature solar selective absorbers 招待有り

    Makoto Shimizu, Hiroo Yugami

    APTSE2019&MNHTE 2019年11月1日

  4. 光レクテナのための酸素不定比性制御に基づくホモ界面MIIMダイオード

    松浦大輔, 清水信, 湯上浩雄

    第80回応用物理学会秋季学術講演会 2019年9月18日

  5. Unidirectional radiative heat transfer using monolithic cube absorber/emitter in solar-thermophotovoltaic systems

    Asaka Kohiyama, Makoto Shimizu, Hiroo Yugami

    6th ASME International Conference of Micro/Nanoscale Heat and Mass Transfer 2019年7月8日

  6. ALD法を用いたフォトニック構造の波長選択吸収特性向上

    清水信, 阿久津宏樹, 湯上浩雄

    2019年5月30日

  7. Effective solar energy conversion via photon management in thermophotovoltaics

    Applied Energy Symposium (AEAB2019) 2019年5月24日

  8. Effective solar energy conversion based on spectral control of thermal radiation via monolithic absorber/emitter 招待有り

    Makoto Shimizu, Asaka Kohiyama, Kana Konno, Hiroo Yugami

    Nano-Micro Conference 2018年12月

  9. 金属ナノ薄膜を用いた微小共振器構造からの低指向性準単色熱放射

    清水信, 矢部雄斗, 小桧山朝華, 井口史匡, 湯上浩雄

    第79回応用物理学会秋季学術講演会 2018年9月20日

  10. Fabrication of Surface Microstructures Based on Spinodal Decomposition for High-Temperature Solar Selective Absorbers 国際会議

    16th International Heat Transfer Conference (IHTC-16) 2018年8月14日

  11. Solar selective absorbers using submicron structures formed by spinodal decomposition 国際会議 招待有り

    Progress in Electromagnetics Research Symposium (PIERS 2018) 2018年8月3日

  12. Forming of conformal multilayer on periodic microstructures for solar selective absorption 国際会議

    18th International Conference on Atomic Layer Deposition 2018年7月30日

  13. 透明導電酸化物埋め込み微細構造を用いた太陽光選択吸収材料

    清水信, 阿部俊郎, 井口史匡, 湯上浩雄

    第55回日本伝熱シンポジウム 2018年5月29日

  14. 太陽熱光起電力発電システムにおけるふく射抽出効率の向上

    小桧山朝華, 清水信, 湯上浩雄

    第65回応用物理学会 春季学術講演会 2018年3月19日

  15. 透明導電酸化物被覆微細構造を用いた太陽光選択吸収材料の耐熱性評価

    清水信, 阿部俊郎, 井口史匡, 湯上浩雄

    第65回応用物理学会 春季学術講演会 2018年3月19日

  16. 光レクテナセルを用いたレーザー光受電システム

    松浦大輔, 清水信,陳強, 湯上浩雄

    第3回宇宙太陽発電シンポジウム 2017年11月29日

  17. 集光太陽光を用いた熱光起電力発電システムの発電試験

    小桧山朝華, 清水信, 湯上浩雄

    平成29年度 一般社団法人日本太陽エネルギー学会・日本風力エネルギー学会 合同研究発表会 2017年10月27日

  18. 透明導電酸化物膜を用いた高波長選択性太陽光選択吸収材料

    清水信, 井口史匡, 湯上浩雄

    機械学会東北支部第53回秋季講演会 2017年9月30日

  19. 熱ふく射スペクトル制御技術を用いた光レクテナシステムにおける光応答ダイオードの特性評価

    松浦大輔, 清水信,陳強, 湯上浩雄

    機械学会東北支部第53回秋季講演会 2017年9月30日

  20. ふく射熱輸送特性と波長選択性の 太陽熱光起電力発電システム効率への影響(Ⅱ)

    小桧山朝華, 清水信, 湯上浩雄

    第78回応用物理学会秋季学術講演会 2017年9月8日

  21. 透明導電酸化物被覆微細構造を用いた高温用太陽光選択吸収材料

    清水信, 阿部俊郎, 井口史匡, 湯上浩雄

    第78回応用物理学会秋季学術講演会 2017年9月8日

  22. High-efficiency solar-thermophotovoltaic systems based on controlling asymmetricity of radiative heat transfer in a monolithic absorber/emitter 国際会議

    Summer Heat Transfer Conference ASME2017 2017年7月11日

  23. A Few Layer Coating on Periodic Shallow Microstructures as a Spectrally Selective Absorber 国際会議

    Summer Heat Transfer Conference ASME2017 2017年7月11日

  24. High-efficiency Solar-thermophotovoltaic Systems Based on Controlling Unidirectional Radiative Heat Transfer with a Monolithic absorber/emitter 国際会議

    NanoRad2017 2017年6月27日

  25. High Spectral Selectivity Based on A Few Layer Structure for Solar-Thermophotovoltaics 国際会議

    NanoRad2017 2017年6月27日

  26. ふく射熱輸送特性と波長選択性の太陽熱光起電力発電システム効率への影響

    小桧山朝華, 清水信, 湯上浩雄

    第64回応用物理学会春季学術講演会 2017年3月17日

  27. 金属―透明誘電体積層構造による熱ふく射スペクトル制御

    清水信, 小桧山朝華, 湯上浩雄

    フィジカルセンサ/マイクロマシン・センサシステム研究会 2016年12月19日

  28. Optical Design of Few-layer Thermal Radiation Emitters for Thermophotovoltaics 国際会議

    International Mechanical Engineering Congress & Exposition 2016年11月11日

  29. 多層膜積層型微細構造による太陽光選択吸収材料

    清水 信, 阿久津 宏樹, 津田 慎一郎, 井口 史匡, 湯上 浩雄

    第33回「センサ・マイクロマシンと応用システム」シンポジウム;メタマテリアル・プラズモニック構造 2016年10月24日

  30. System design and experiment of solar-thermophotovoltaic generation based on spectrally selective absorber/emitter 国際会議

    Solar PACES 2016 Conference 2016年10月13日

  31. High-temperature solar selective absorbers based on a transparent conductive oxide film coated metal microstructures 国際会議

    Solar PACES 2016 Conference 2016年10月13日

  32. 熱輸送効率向上による太陽熱光起電力発電システムの高効率化

    小桧山朝華, 清水信, 湯上浩雄

    第77回応用物理学会秋季学術講演会 2016年9月15日

  33. 金属―誘電体積層構造を用いた高温用太陽光選択吸収材料

    清水 信, 阿久津 宏樹, 津田 慎一郎, 井口 史匡, 湯上 浩雄

    第77回応用物理学会秋季学術講演会 2016年9月15日

  34. 高温フォトニクスによる太陽熱利用技術の高度化 招待有り

    湯上浩雄, 清水信

    第77回応用物理学会秋季学術講演会 2016年9月13日

  35. Solar-thermophotovoltaic systems using spectrally selective absorber/emitter based on metal-dielectric multilayer 国際会議

    Asaka Kohiyama, Makoto Shimizu, Hiroo Yugami

    SPIE Optics + Photonics for Sustainable Energy 2016年5月

  36. Tailoring the spectral emissivity of few-layer structures with interference effects 国際会議

    WE-Heraeus-Seminar: Heat transfer and heat conduction on the nanoscale 2016年4月

  37. 熱輻射による半透明体の輻射輸送促進

    津田慎一郎, 清水信, 井口史匡, 湯上浩雄

    第63回応用物理学会春季学術講演会 2016年3月20日

  38. Low-directivity quasi-monochromatic thermal radiation from microcavities covered by thin metal film

    Asaka Kohiyama, Makoto Shimizu, Fumitada Iguchi, Hiroo Yugami

    ASME 2016 5th International Conference on Micro/Nanoscale Heat and Mass Transfer, MNHMT 2016 2016年1月1日

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    © 2016 by ASME. Here, closed-end microcavity is proposed in which a semi-transparent metal film was formed atop microcavity. The structure shows weak angular dependence as well as quasimonochromatic absorptance. Au is employed as material of the cavity walls and the covering thin film. Quasi-monochromatic absorption from the structure is observed in numerical simulation. High quality factor (Q factor) is obtained by strong confinement in the closed-end microcavity. Asymmetric and quasi-monochromatic absorption band with a Q factor of ∼28 at 1.85 μm was observed. This value was about 4-fold larger than that of the open-end microcavity. Additionally, the closed-end microcavity structure filled with SiO2in cavity exhibits isotropic and quasi-monochromatic thermal radiation over a wide solid angle. This result suggests that both quasimonochromatic and low-directivity absorptance can be realized by using this configuration.

  39. Spectral control of thermal radiation using metal-dielectric multilayers for high-temperature usage over 1000°C

    Makoto Shimizu, Asaka Kohiyama, Fumitada Iguchi, Hiroo Yugami

    ASME 2016 5th International Conference on Micro/Nanoscale Heat and Mass Transfer, MNHMT 2016 2016年1月1日

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    © 2016 by ASME. The spectrally selective coating technology which can be applicable for solar-thermophotovoltaic (solar-TPV) generation systems is described in this paper. In solar-TPV system, the spectrally selective absorber plays a key role to obtain highefficiency. The technologies of controlling thermal radiation spectrum at temperature over 1000oC, however, have not been established yet. We focus on metal-dielectric multi-layer coating. This selective coating shows enormously high absorptance at short wavelength range and sharp cutoff property. Thermal stability test confirms that this multi-layer structure can be one of the candidates for the selective coatings for solar-TPV systems.

  40. Solar-thermophotovoltaic systems using spectrally selective absorber/emitter based on metal-dielectric multilayer

    A. Kohiyama, M. Shimizu, H. Yugami

    Proceedings of SPIE - The International Society for Optical Engineering 2016年1月1日

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    © 2016 SPIE. In this paper, high-efficiency STPV systems are investigated using spectrally selective absorber/emitter consisted of metal-dielectric multilayer and a GaSb TPV cell. A solar-thermophotovoltaic (STPV) system is expected to as highefficiency solar energy conversion using single-junction photovoltaic (PV) cells. However, the reached experimental system efficiency has been still low because spectral control of emitter is not sufficient. Narrowband thermal radiation from the emitter is effective for obtaining high-efficiency STPV systems, exceeding the Shockley-Queisser limit. From theoretical analysis, the narrowband thermal emitter can leads to obtain PV conversion efficiency over 45% at Qvalue= 30 and 1300K. The spectrally selective absorber/emitter was also investigated to obtain high ηPV. The ηPV = 23.5% was estimated by the fabricated emitter spectrum, which exceeds the Shockley-Queisser limit of 19.6% for a GaSb bandgap of 0.67 eV. The entire STPV system and the power generation tests were conducted using the fabricated absorber/emitter. The total system efficiency 4.9% at 1505K was obtained under an irradiance of 109 Wcm-2.

  41. A solar thermophotovoltaic system using spectrally controlled monolithic planar thermal emitter/absorber 招待有り

    Hiroo Yugami, Asaka Kohiyama, Makoto Shimizu, Fumitada Iguchi

    ASME 2016 5th International Conference on Micro/Nanoscale Heat and Mass Transfer, MNHMT 2016 2016年1月1日

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    © 2016 by ASME. Solar-thermophotovoltaic system is expected to have high efficiency by converting wide spectral range solar energy into useful thermal radiation energy. However, the experimental STPV system shows much lower efficiency than theoretical one. To achieve high-efficiency, it is essential to obtain good spectrally matching between thermal radiation spectrum and PV cells spectral response. In this paper, the power generation tests using the whole configuration of the STPV system is described. The conversion efficiency of GaSb PV cell is estimated to be 20 to 23% against to the light intensity irradiated on the PV cell surface. The net system efficiency of 1.9% can be achieved. The application of thermal storage system to the STPV is also considered.

  42. 熱ふく射スペクトル制御技術を用いた太陽熱光起電力発電システム

    小桧山朝華, 清水信, 井口史匡, 湯上浩雄

    第76回応用物理学会秋季学術講演会 2015年9月15日

  43. マイクロキャビティ構造からの波長選択性熱ふく射スペクトル狭帯域化

    小桧山朝華, 清水信, 井口史匡, 湯上浩雄

    第62回応用物理学会春季学術講演会 2015年3月13日

  44. 波長選択性熱放射による狭空間内における電子デバイス冷却技術

    津田慎一郎, 清水信, 井口史匡, 湯上浩雄

    第62回応用物理学会春季学術講演会 2015年3月11日

  45. 熱放射スペクトル制御材料を用いた高効率ソーラー熱光起電力発電

    清水 信, 小桧山 朝華, 酒井 淳, 柳澤 邦彦, 井口 史匡, 湯上 浩雄

    第62回応用物理学会春季学術講演会 2015年3月11日

  46. ナローギャップPVセルを用いた熱光起電力発電 招待有り

    湯上浩雄, 清水信

    応用電子物性分科会研究会 2015年

  47. 固体酸化物形燃料電池用Ni-YSZ サーメットの高温機械特性

    KASEMCHAI CHAIPRASOBPHOL, 井口 史匡, 清水 信, 湯上 浩雄

    2014年度電気化学会秋季大会 2014年9月27日

  48. ソーラー熱光起電力発電における熱放射スペクトル制御材料の高温特性

    清水信, 小桧山朝華, 井口史匡, 湯上浩雄

    第75回応用物理学会秋季学術講演会 2014年9月17日

  49. SOFC/SOEC based on yttrium doped barium zirconate perovskite type proton conductors 国際会議

    Takahumi Kumagai, Fumitada Iguchi, Makoto Shimizu, Hiroo Yugami

    17th International Conference on Solid State Protonic Conductors (SSPC-17) 2014年9月14日

  50. HIGH-TEMPERATURE PHOTONICS FOR ADVANCED SOLAR ENERGY APPLICATIONS 国際会議

    Makoto Shimizu, Asaka Kohiyama, Fumitada Iguch, Hiroo Yugami

    Grand Renewable Energy 2014 International Conference 2014年7月27日

  51. 面内圧縮応力状態下における安定化ジルコニアの電気的特性

    井口史匡, 山根拓也, 清水信, 湯上浩雄

    日本機械学会 M&M2014材料力学カンファレンス 2014年7月18日

  52. Application of transparent conductive oxides films for high-temperature solar selective absorbers 国際会議

    Asaka Kohiyama, Makoto Shimizu, Hiroaki Kobayashi, Fumitada Iguchi, Hiroo Yugami

    ASME 2014 8th International Conference on Energy Sustainability & 12th Fuel Cell Science, Engineering and Technology Conference 2014年6月29日

  53. High-efficiency thermophotovoltaic system by quasi-monochromatic thermal radiation 国際会議

    Makoto Shimizu, Mari Suzuki, Asaka Kohiyama, Fumitada Iguchi, Hiroo Yugami

    ASME 2014 8th International Conference on Energy Sustainability & 12th Fuel Cell Science, Engineering and Technology Conference 2014年6月29日

  54. Application of high-temperature photonics for solar energy systems 国際会議

    Makoto Shimizu, Asaka Kohiyama, Hiroaki Kobayashi, Mari Suzuki, Fumitada Iguchi, Hiroo Yugami

    NanoRad 2014 2014年6月7日

  55. 高温フォトニクスによるふく射熱輸送の高効率化

    清水信, 小桧山朝華, 井口史匡, 湯上浩雄

    電気学会マイクロマシン・センサシステム研究会 2014年5月27日

  56. 10% efficiency solar thermophotovoltaic systems using spectrally controlled monolithic planar absorber/emitters 国際会議

    Makoto Shimizu, Asaka Kohiyama, Hiroo Yugami

    SPIE photonics europe 2014年4月14日

  57. 透明導電膜を用いた太陽光選択吸収材料の吸収特性向上

    清水信, 鈴木麻里, 井口史匡, 湯上浩雄

    第61回応用物理学会春季学術講演会 2014年3月17日

  58. GaSb 単接合セルを用いた集光太陽光による高効率熱光起電力発電システム

    小桧山朝華, 小林大晃, 清水信, 井口史匡, 湯上浩雄

    第61回応用物理学会春季学術講演会 2014年3月17日

  59. 高ふく射性SiC系繊維を用いた高温炉におけるエネルギー回収

    小島 匠, 酒井 淳, 清水 信, 井口 史匡, 湯上 浩雄

    第5回マイクロ・ナノシンポジウム 2014年3月14日

  60. Thermal management of power sources for mobile electronic devices based on micro-SOFC

    S. Murayama, F. Iguchi, M. Shimizu, H. Yugami

    Journal of Physics: Conference Series 2014年1月1日

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    © Published under licence by IOP Publishing Ltd. Small power sources based on micro-SOFC for mobile electronic devices required two conditions, i,e, thermally compatibility and thermally self-sustain, because of high operating temperature over 300oC. Moreover, high energy efficiency was also required. It meant that this system should be designed considering thermal management. In this study, we developed micro-SOFC packages which have three functions, thermal insulation, thermal recovery, and self-heating. Heat conduction analysis based on finite element method, and thermochemical calculation revealed that vacuum thermal insulation was effective for size reduction and gas-liquid heat exchanger could reduce the temperature of outer surface. We fabricated the package with three functions for proof of concept and evaluated. As a result, it was suggested that developed package could satisfy both two requirements with high efficiency.

  61. Application of transparent conductive oxides films for high-temperature solar selective absorbers

    Makoto Shimizu, Mari Suzuki, Asaka Kohiyama, Fumitada Iguchi, Hiroo Yugami

    ASME 2014 8th International Conference on Energy Sustainability, ES 2014 Collocated with the ASME 2014 12th International Conference on Fuel Cell Science, Engineering and Technology 2014年1月1日

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    Copyright © 2014 by ASME. At present, the utilization of thermal energy from sunlight has been widely adopted as the working principle of concentrated solar power (CSP) generation systems. In this research, we suggest a CSP technology based on the properties of transparent conductive oxide (TCO) films on metal substrates which is compatible with mass production of solar selective absorbers that can be utilized at high temperatures. TCO material has plasma wavelength in infrared region. Therefore the electromagnetic wave with shorter wavelength than plasma wavelength goes through the material, while the electromagnetic wave with longer wavelength is reflected on the surface. By coating metal surface with a TCO film, interference is occurred in transparent wavelength range of TCO. Therefore, solar energy is highly absorbed, though thermal radiation from the absorber is suppressed. The optical property of fabricated TCO coated metal is well consistent with the simulated property. It is revealed that the performance of the absorber is improved by fabricating microstructures on the metal substrate. Thermal stability is confirmed at 700°C in vacuum for 3 hours. Solar absorptance and hemispherical emittance of the fabricated absorber are 0.82 and 0.17, respectively, which is comparable to that of commercialized absorbers.

  62. High-efficiency thermophotovoltaic system by quasi-monochromatic thermal radiation

    Asaka Kohiyama, Makoto Shimizu, Hiroaki Kobayashi, Fumitada Iguchi, Hiroo Yugami

    ASME 2014 8th International Conference on Energy Sustainability, ES 2014 Collocated with the ASME 2014 12th International Conference on Fuel Cell Science, Engineering and Technology 2014年1月1日

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    Copyright © 2014 by ASME. Efficiency of solar-thermophotovoltaic (TPV) systems can be improved by controlling spectral property of thermal radiation to match the photovoltaic (PV) cells spectral response. We developed a spectrally selective emitter which can emit quasi-monochromatic thermal radiation to improve the efficiency of TPV systems. From the evaluation by the detailed-balance model for gallium antimonite (GaSb) TPV cells, the photovoltaic conversion efficiency over 50 % is achievable in the case of the emitter temperature over 1800K and emitter Q-value over 15. The numerical simulation based on Rigorous-Coupled Wave Analysis revealed that the quasi-monochromatic thermal radiation can be obtained by closed-end microcavity structure. A solar-TPV system equipped with a solar-simulator is fabricated to evaluate the effect of spectrally selective emitter. By using GaSb TPV cells and spectrally selective emitter based on dielectric layer coating, photovoltaic conversion efficiency of 26% and total efficiency of 7.7% are obtained at emitter temperature of 1654 K under 384 suns.

  63. A solar thermophotovoltaic generation with a monolithic planar absorber/emitter material

    Hiroaki Kobayashi, Jun Sakai, Asaka Kohiyama, Makoto Shimizu, Fumitada Iguchi, Hiroo Yugami

    Optics InfoBase Conference Papers 2013年12月1日

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    A planar absorber/emitter in solar thermophotovoltaic system reaches high temperature with a small concentration ratio because of low thermal radiation loss. Using this planar absorber/emitter, the net efficiency is estimated to be 21%. Renewable Energy and the Environment Congress © 2013.

  64. A solar thermophotovoltaic generation with a monolithic planar absorber/emitter material

    Hiroaki Kobayashi, Jun Sakai, Asaka Kohiyama, Makoto Shimizu, Fumitada Iguchi, Hiroo Yugami

    Optics InfoBase Conference Papers 2013年12月1日

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    A planar absorber/emitter in solar thermophotovoltaic system reaches high temperature with a small concentration ratio because of low thermal radiation loss. Using this planar absorber/emitter, the net efficiency is estimated to be 21%. Renewable Energy and the Environment Congress © 2013.

  65. A solar thermophotovoltaic generation with a monolithic planar absorber/emitter material

    Hiroaki Kobayashi, Jun Sakai, Asaka Kohiyama, Makoto Shimizu, Fumitada Iguchi, Hiroo Yugami

    Optics InfoBase Conference Papers 2013年12月1日

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    A planar absorber/emitter in solar thermophotovoltaic system reaches high temperature with a small concentration ratio because of low thermal radiation loss. Using this planar absorber/emitter, the net efficiency is estimated to be 21%. Renewable Energy and the Environment Congress © 2013.

  66. Practicable fabrication technology of high-temperature photonic materials for thermophotovoltaic systems 国際会議

    Makoto Shimizu, Hiroaki Kobayashi, Kunihiko Yanagisawa, Fumitada Iguchi, Hiroo Yugami

    2013 Renewable Energy and the Environment Meeting 2013年11月3日

  67. A Solar Thermophotovoltaic Generation with a Monolithic Planar Absorber/emitter Material 国際会議

    Hiroaki Kobayashi, Jun Sakai, Asaka Kohiyama, Makoto Shimizu, Fumitada Iguchi, Hiroo Yugami

    2013 Renewable Energy and the Environment Meeting 2013年11月3日

  68. High-temperature solar selective absorbers using transparent conductive oxide coated metal 国際会議

    Makoto Shimizu, Mari Suzuki, Fumitada Iguchi, Hiroo Yugami

    2013 ISES Solar World Congress 2013年11月3日

  69. High-temperature photonics using self-organization of superalloys for solar selective absorbers 国際会議

    Makoto Shimizu, Kiyotaka Konno, Hiroaki Kobayashi, Fumitada Iguchi, Hiroo Yugami

    2013 ISES Solar World Congress 2013年11月3日

  70. Spectrally Controlled Thermal Radiation Based on Surface Microstructures for High-Efficiency Solar Thermophotovoltaic System 国際会議

    Asaka Kohiyama, Hiroaki Kobayashi, Makoto Shimizu, Fumitada Iguchi, Hiroo Yugami

    2013 ISES Solar World Congress 2013年11月3日

  71. Relationship between Electrical Properties and Stress Field in Solid Electrolyte Thin Films 国際会議

    Yohei Osawa, Fumitada Iguchi, Makoto Shimizu, Hiroo Yugami

    13th international symposium on Solid Oxide Fuel Cells (SOFC-XIII) 2013年10月6日

  72. Evaluation of Stress Condition of Operated Anode Supported-Type SOFC under Operating Conditions Based on Raman Scattering Spectroscopy 国際会議

    Shoma Onuki, Syo Onodera, Fumitada Iguchi, Makoto Shimizu, Tatsuya Kawada, Hiroo Yugami

    13th international symposium on Solid Oxide Fuel Cells (SOFC-XIII) 2013年10月6日

  73. Stress Conditions Transition by Thermal Annealing in Barium Zirconate Based Proton Conducting Thin Films Fabricated Using PLD Method 国際会議

    Taro Fukushige, Fumitada Iguchi, Makoto Shimizu, Hiroo Yugami

    13th international symposium on Solid Oxide Fuel Cells (SOFC-XIII) 2013年10月6日

  74. Design and fabrication of micro SOFC for the power source of mobile electric devices 国際会議

    Shoya Murayama, Fumitada Iguchi, Yu Inagaki, Makoto Shimizu, Shuji Tanaka, Hiroo Yugami

    13th international symposium on Solid Oxide Fuel Cells (SOFC-XIII) 2013年10月6日

  75. Ni 基超合金の自己組織化に基づく熱輻射スペクトル制御材料の作製

    清水 信, 今野 晴天, 小林 大晃, 井口 史匡, 湯上 浩雄

    第74回応用物理学会秋季学術講演会 2013年9月16日

  76. 透明導電膜を用いた太陽光選択吸収材料のカットオフ波長制御

    鈴木麻里, 清水信, 井口史匡, 湯上浩雄

    第74回応用物理学会秋季学術講演会 2013年9月16日

  77. Residual Stress and Strain in Thin Films Fabricated Using PLD Method 国際会議

    Fumitada Iguchi, Yohei Osawa, Taro Fukushige, Hiroo Yugami

    19th International Conference on Slid State Ionics (SSI-19) 2013年6月2日

  78. Ni 基超合金の自己組織化による周期的微細構造作製

    清水信, 今野晴天, 小林大晃, 井口史匡, 湯上浩雄

    第60回応用物理学会春季学術講演会 2013年3月27日

  79. 透明導電酸化物膜を用いた太陽光選択吸収材料

    鈴木麻里, 清水信, 井口史匡, 湯上浩雄

    第61回応用物理学会春季学術講演会 2013年3月27日

  80. A solar thermophotovoltaic generation with a monolithic planar absorber/emitter material

    Hiroaki Kobayashi, Jun Sakai, Asaka Kohiyama, Makoto Shimizu, Fumitada Iguchi, Hiroo Yugami

    Optics InfoBase Conference Papers 2013年1月1日

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    A planar absorber/emitter in solar thermophotovoltaic system reaches high temperature with a small concentration ratio because of low thermal radiation loss. Using this planar absorber/emitter, the net efficiency is estimated to be 21%. Renewable Energy and the Environment Congress © 2013.

  81. Practicable fabrication technology of high-temperature photonic materials for thermophotovoltaic systems

    Makoto Shimizu, Hiroaki Kobayashi, Kunihiko Yanagisawa, Fumitada Iguchi, Hiroo Yugami

    Optics InfoBase Conference Papers 2013年1月1日

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    The high-temperature photonic materials fabricated by practicable technology is described. The high-temperature photonic material using self-organization of a super-alloys and a monolithic planer absorber/emitter with multi-layer coating is obtained. Renewable Energy and the Environment Congress © 2013.

  82. A solar thermophotovoltaic generation with a monolithic planar absorber/emitter material

    Hiroaki Kobayashi, Jun Sakai, Asaka Kohiyama, Makoto Shimizu, Fumitada Iguchi, Hiroo Yugami

    Optics InfoBase Conference Papers 2013年1月1日

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    A planar absorber/emitter in solar thermophotovoltaic system reaches high temperature with a small concentration ratio because of low thermal radiation loss. Using this planar absorber/emitter, the net efficiency is estimated to be 21%. Renewable Energy and the Environment Congress. © 2013.

  83. 透明導電酸化物の太陽光選択吸収材料への応用

    清水信, 今野晴天, 井口史匡, 湯上浩雄

    平成24年度日本太陽エネルギー学会・日本風力エネルギー学会・Korea Solar Energy Society合同研究発表会 2012年11月7日

  84. 周期的微細構造を持つ耐熱性合金を用いた太陽光選択吸収材料の作製

    今野晴天, 清水信, 井口史匡, 湯上浩雄

    平成24年度日本太陽エネルギー学会・日本風力エネルギー学会・Korea Solar Energy Society合同研究発表会 2012年11月7日

  85. High-Temperature Solar Selective Absorbers Based on Interface Effects in Refractory Metals Coated with Transparent Conductive Oxides 国際会議

    M. Shimizu, F. Iguchi, H. Yugami

    ASME 2012 6th International Conference on Energy Sustainability & 10th Fuel Cell Science, Engineering and Technology Conference 2012年7月23日

  86. Application Technologies of Spectrally Controlled Thermal Radiation Using Microstructures for Energy Systems 国際会議

    M. Shimizu, F. Iguchi, H. Yugami

    International Workshop on Nano-Micro Thermal Radiation 2012年5月23日

  87. High-temperature solar selective absorbers based on interface effects in refractory metals coated with transparent conductive oxides

    Makoto Shimizu, Fumitada Iguchi, Hiroo Yugami

    ASME 2012 6th International Conference on Energy Sustainability, ES 2012, Collocated with the ASME 2012 10th International Conference on Fuel Cell Science, Engineering and Technology 2012年1月1日

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    At present, the utilization of thermal energy from sunlight has been widely adopted as the working principle of concentrated solar power (CSP) generation systems. In this research, we suggest a CSP technology based on the properties of transparent conductive oxide (TCO) thin films on metal substrates which is compatible with mass production of solar selective absorbers that can be utilized at high temperatures. Since the plasma wavelength of TCO materials is in the infrared region, electromagnetic waves with wavelengths longer than the plasma wavelength are reflected at the surface, whereas electromagnetic waves with shorter wavelengths pass through the surface layer and reach the substrate. In other words, a TCO thin film behaves as an antireflection film only in the transparency range of TCO coating. This phenomenon is demonstrated through numerical simulations based on rigorous coupled-wave analysis (RCWA). The prepared samples also show favorable spectral selectivity and satisfactory performance as solar selective absorbers, with a solar absorptance of 0.76, a thermal emittance of 0.12 at 800°C and a spectral selectivity of 6.5 at 800°C. Copyright © 2012 by ASME.

  88. 高温フォトニクス材料による太陽エネルギー利用

    湯上浩雄, 清水信, 前神有里子, 井口史匡

    応用物理学会東北支部第66回学術講演会特別シンポジウム 2011年12月3日

  89. High-temperature solar selective absorber material using surface microcavity structures

    Makoto Shimizu, Kimio Takeuchi, Hitoshi Sai, Fumitada Iguchi, Noriko Sata, Hiroo Yugami

    ASME 2011 5th International Conference on Energy Sustainability, ES 2011 2011年12月1日

    詳細を見る 詳細を閉じる

    The spectral properties of thermal radiation can be controlled by surface microstructures with feature size in the optical wavelength range. We applied this technology to solar selective absorbers for concentrated solar power (CSP) generation systems. We investigated the spectral properties and thermal stability of two-dimensional periodic microstructures on a tungsten (W) surface to develop solar selective absorbers for high-temperature applications. The developed absorbers exhibited good spectral selectivity and sufficient thermal stability under vacuum. Although we could verified that the microstructured solar selective absorbers improved CSP efficiency, this method cannot be put into practical use because of cost and time, and also because there is currently no technology for fabricating surface gratings on high melting point materials over a large area. Therefore, we used W-Cu alloys to investigate an approach to mass production of surface microcavity structures over a large area. We then confirmed that the absorptivity in the visible light range could be increased by using this simple method. Copyright © 2011 by ASME.

  90. Development of High Temperature Solar Selective Absorber Using Refractory Material with Surface Microstructures 国際会議

    Makoto Shimizu, Kimio Takeuchi, Hitoshi Sai, Fumitada Iguchi, Hiroo Yugami

    8th International Conference on Flow Dynamics 2011年11月9日

  91. 金属-絶縁体相転移物質を用いた環境応答型波長選択性熱輻射の空間熱制御への適用

    清水信, 井口史匡, 湯上浩雄

    2011年秋季 第72回 応用物理学会学術講演会 2011年8月28日

  92. High Temperature Solar Selective Absorber Material Using the Surface Microcavity Structures 国際会議

    M. Shimizu, K. Takeuchi, H. Sai, F. Iguchi, N. Sata, H. Yugami

    ASME 2011 5th International Conference on Energy Sustainability & 9th Fuel Cell Science 2011年8月7日

  93. 波長選択性太陽光吸収材料としての周期的微細構造を持つ耐熱性合金の作製

    今野晴天, 清水信, 井口史匡, 湯上浩雄

    東北支部第47期総会・講演会 2011年3月13日

  94. Application of thermal radiation control by surface gratings to advance cooling system for electronic devices 国際会議

    M. Shimizu, H. Yugami

    7th International Conference on Flow Dynamics 2010年11月

  95. Application of thermal radiation control by surface gratings to energy efficient windows 国際会議

    M. Shimizu, T. Kawano, F. Iguchi, H. Yugami

    Renewable Energy 2010 2010年7月

  96. 電子デバイス冷却への波長選択性熱放射の適用

    清水信, 湯上浩雄

    東北支部第46期総会・講演会 2010年3月12日

  97. 123 電子デバイス冷却への波長選択性熱放射の適用(学生賞IV,一般講演)

    清水 信, 湯上 浩雄

    東北支部総会・講演会 講演論文集 2010年

  98. Application of Spectral Selective Thermal Radiation for Cooling Electronic device Packaged in Resin 国際会議

    M. Shimizu, H. Yugami

    6th International Conference on Flow Dynamics 2009年11月4日

  99. 波長選択性熱放射による樹脂パッケージされた電子デバイスの冷却促進

    清水信, 湯上浩雄

    日本機械学会 2009年度年次大会 2009年9月14日

  100. 熱放射スペクトル制御による樹脂パッケージされた電子デバイスの冷却促進

    清水信, 湯上浩雄

    第56回応用物理学関係連合講演会 2009年3月29日

  101. J0103-4-2 波長選択性熱放射による樹脂パッケージされた電子デバイスの冷却促進(電子情報機器,電子デバイスの強度・信頼性評価と熱制御(4))

    清水 信, 湯上 浩雄

    年次大会 2009年

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    This paper describes the new technique of cooling electronic devices packaged in resin. In recent years, cooling electronic devices becomes very serious problem. To enhance thermal radiation from electronic devices, this problem is improved because 20%-40% of heat is dissipated by radiative heat transfer. We report new technique about cooling electronic devices to control radiative spectra from its surface. Resin which packages an electronic device prevents radiation from going outside air. We consider that radiation from electronic devices transmits resin to control radiative spectra. As a result, cooling performance improved. A spectral selective emitter which consists of periodical micron meter scale two-dimensional grating on metal surface can control radiative spectra. In this research, we decide an optimal selective emitter design from simulation and fabricated it by micro-machining technology. Finally, the fact that using spectral selective emitter enhanced cooling performance is obtained from cooling performance test.

  102. 波長選択性熱放射によるパッケージされた電子デバイスからの排熱促進

    清水信, 湯上浩雄, 吉岡文孝, 豊永隆

    第69回応用物理学会学術講演会 2008年9月4日

  103. 光レクテナのための酸素不定比性制御に基づくホモ界面MIIMダイオード(II)

    松浦大輔, 清水信, 湯上浩雄

    第67回応用物理学会春季学術講演会

︎全件表示 ︎最初の5件までを表示

産業財産権 4

  1. 宇宙用放熱素子及びその設計方法と製造方法

    佐々木 浩司, 高田 昭夫, 松野 雄介, 安藤 麻紀子, 田中 洸輔, 矢部 高宏, 湯上 浩雄, 清水 信

    産業財産権の種類: 特許権

  2. ナノインプリント方法によるアルミニウムシートからなる波長選択性熱放射材料の製造方法

    湯上 浩雄, 清水 信, 豊永 隆, 木村 直史, 吉岡 文孝

    産業財産権の種類: 特許権

  3. 熱吸収材及びその製造方法

    山田 隆俊, 高田 昭夫, 湯上 浩雄, 井口 史匡, 清水 信

    特許第6224345号

    産業財産権の種類: 特許権

  4. 波長選択性熱放射または熱吸収材料の製造方法

    湯上 浩雄, 井口 史匡, 清水 信

    特許第5725658号

    産業財産権の種類: 特許権

共同研究・競争的資金等の研究課題 14

  1. 熱光化学反応による先進的水素生成技術の創製

    湯上 浩雄, 清水 信

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research

    研究種目:Grant-in-Aid for Scientific Research (B)

    研究機関:Tohoku University

    2023年4月1日 ~ 2026年3月31日

  2. 光波発電を用いた赤外光エネルギー利用

    清水信

    2020年10月 ~ 2025年9月

  3. 再結晶強化組織とイオン注入組織安定化による「再結晶脆化しない」超耐熱金属の新創生

    野上 修平, 能登 裕之, 清水 信

    2022年6月30日 ~ 2025年3月31日

  4. 熱輻射定在波によるプラズモン誘起電荷分離を用いたメタン改質水素生成反応促進

    湯上 浩雄, 清水 信

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research

    研究種目:Grant-in-Aid for Challenging Research (Exploratory)

    研究機関:Tohoku University

    2021年7月9日 ~ 2024年3月31日

  5. 固体イオン導電体における結晶学的力学因子の解明

    井口 史匡, 清水 信

    2021年4月1日 ~ 2024年3月31日

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    申請者の異動に伴い2021年度は東北大と日本大学で分かれて研究を遂行せざる負えなくなり,研究の実施計画を変更し研究を行った。実施計画は既有装置の改良と力学因子の測定であり大きく3つに分けた。1つ目はレーザドップラー計を購入,in-situでひずみと導電率が同時計測可能な装置へのアップグレードとそれによる酸化物イオン導電体の力学因子の評価,2つ目は二軸で弾性波を導入可能となるよう弾性波を用いた実験装置の改良,3つ目はガーネット型,ペロブスカイト型,リン酸型等のリチウムイオン導電体に対して既有の装置を用いた力学因子の評価であった。 レーザドップラー振動計を用いたひずみの計測は既有の装置に追加しただけでは,振動変位に導波管の軸方向振動に加え,軸に垂直方向の大きな振動変位が加わり正確な評価が行えず,装置に用いた導波管の交換を余儀なくされたが最終的には,軸方向の弾性波により物質に加わるひずみのin-situ評価が行えるようになり,酸化物イオン導電体でのひずみ,導電率の同時計測を行うことができ力学因子の評価を行うことができた。また,2つ目の二軸で弾性波を導入する装置へのアップグレードについては導入される二軸ひずみの正確な評価には二軸に加え斜め方向の三軸のひずみを評価する必要があったため,今年度はそれを考慮したアップグレード方法の検討までを行った。 In-situ計測,二軸導入の双方について問題が生じ,その解決に時間を要したため3つ目のリチウムイオン導電体の力学因子の評価は弾性波では行わず,粉体プレスを用いた等方圧を用いた行った。ガーネット型,ペロブスカイト型,リン酸型の異なる結晶構造を持つ3種において最大250MPaの等方圧を印加し導電率を計測した結果,導電率の変化率は導電体毎に異なり,さらに結晶構造と導電経路の双方と関連があることが明らかになった。

  6. 近距離秩序を有する自己組織化ナノ構造を用いた大面積メタサーフェスの実現

    清水 信

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research

    研究種目:Grant-in-Aid for Scientific Research (C)

    研究機関:Tohoku University

    2021年4月1日 ~ 2024年3月31日

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    従来の人工構造表面(メタサーフェス)による熱輻射スペクトル制御技術では構造の周期性、均一性が制御特性に大きく関与するため、大面積作製プロセスにおいて発生する構造欠陥によって熱輻射スペクトル制御性能が大きく低下してしまうという課題があった。これに対し本研究ではアモルファス配列ナノ構造を用いた大面積メタサーフェスの実現を目的とする。短距離秩序のみ非周期構造では電子と同様に光子のアンダーソン局在が生じ、非周期でもフォトニックバンドギャップが形成するといった特異な光学特性の発現が知られている。これらの現象に基づくスペクトル特性は本質的に構造欠陥の影響を受けにくいと考えられる。申請者はスピノーダル分解に基づくアモルファス配列構造作製技術を報告しており、本研究では構造パラメータが制御特性へ与える影響を明らかにし、非周期構造でも高いスペクトル制御性を有する技術を確立する。これにより、高いスペクトル制御特性を有するメタサーフェス大面積化技術を実現し、微細構造を用いたスペクトル制御技術の実用化を目指す。 本年度はNi基超合金のスピノーダル分解に起因するアモルファス配列構造において配列性の熱処理条件等による制御性を評価し、溶体化処理後の冷却速度によって配列の制御が可能であることを見出した。また、配列の変化によりスペクトル制御性も変化することを明らかにした。さらに、数値シミュレーションを用いたバンド解析を行い、アモルファス配列構造作製後のSEM像からフォトニックバンド構造の解析を行った。

  7. 熱光起電力発電を用いた廃棄物発電技術の開発

    山田裕史, 掃部宏文, 湯上浩雄, 清水信

    2018年4月 ~ 2021年1月

  8. シリカエアロゲル多層膜フォトニック構造を用いた超断熱スペクトル制御

    清水 信

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Early-Career Scientists

    研究種目:Grant-in-Aid for Early-Career Scientists

    研究機関:Tohoku University

    2018年4月1日 ~ 2020年3月31日

    詳細を見る 詳細を閉じる

    本研究では太陽エネルギーなど熱ふく射光の高効率変換技術を実現するために重要な高温における熱輻射スペクトル制御技術の開発を目的としてシリカエアロゲルを用いた多層膜フォトニック構造を実現することによる新しい熱伝達制御技術の確立を目指している。 平成30年度は光学シミュレーションを用いた高屈折率膜の材料選定および膜厚最適化を進めると共に、多層膜フォトニック構造の実現のために重要となる数百nmオーダーのシリカエアロゲル薄膜の作製を目標として研究を実施した。多層膜フォトニック構造を用いることでフォトニックバンドギャップにおいて輻射熱伝達をほぼゼロにすることができる。フォトニックバンドギャップ帯域は構成される材料の屈折率差に依存するため、低屈折材料であるシリカエアロゲルの相手材料はできる限り高屈折率である必要がある。シリコンおよびβ-鉄シリサイドを試した結果シリコンを用いた場合に広帯域なフォトニックバンドギャップが得られ、良好な熱輻射スペクトル制御が可能であることがわかった。これは高い屈折率の実部と低い屈折率の虚部を有することに起因している。 シリカエアロゲルはシリケートの架橋構造を含むゲルを超臨界乾燥させ作製した。TEOSをアルコール溶媒中に分散させ、触媒を入れることで架橋が開始しゲル粘度が上昇する。ゲル粘度を調整して気泡密度および膜厚を最適化し、目的の膜厚を有するシリカエアロゲル薄膜を作製することができた。更に作製したシリカエアロゲル上にスパッタでシリコン薄膜を形成した後、もう1層のシリカエアロゲル薄膜層の形成を行った。作製試料は想定通りのフォトニックバンドギャップを示しており、本研究で目的とするシリカエアロゲル多層膜フォトニック構造の実現に大きく近づくことができたと考えている。

  9. ふく射スペクトル制御型熱ダイオードを用いた高効率ソーラー熱光起電力発電

    湯上 浩雄, 金森 義明, 清水 信, 井口 史匡

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

    研究種目:Grant-in-Aid for Scientific Research (A)

    研究機関:Tohoku University

    2016年4月1日 ~ 2019年3月31日

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    ソーラー熱光起電力発電は単接合セルで多接合セル並みの高効率発電が期待でき、蓄熱システムとの親和性が高いことから次世代太陽エネルギー変換技術として期待されている技術である。本研究の成果である熱輻射スペクトル制御に基づく熱ダイオード技術は入力した太陽光を非常に高い効率で光起電力セルまで導くための重要な技術である。本研究開発によって実験的にGaSbセルを用いたシステムとしては世界最高効率である変換効率5.6%を達成し、変換効率20%以上が期待できるシステムを構築することができた。

  10. 太陽光の準単色化によるレクテナソーラーセルの高効率化

    湯上 浩雄, 金森 義明, 清水 信, 井口 史匡

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research

    研究種目:Grant-in-Aid for Challenging Exploratory Research

    研究機関:Tohoku University

    2015年4月1日 ~ 2018年3月31日

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    電磁波のエネルギーを電力へ直接変換可能なレクテナシステムにおいてマイクロ波領域ではこれまでに90%以上の変換効率が実現されている。同様の原理で太陽光を直接変換するレクテナソーラーセルに関する研究が近年盛んに行われているが、未だ原理検証段階に留まっている。本研究ではレクテナを用いた太陽エネルギー変換技術の実現を目指し、微小共振器構造を用いることで太陽光を準単色化する方法を開発した。加えて近赤外―可視光域(>100THz)の光に応答可能なダイオードが金属―絶縁体―金属(MIM)トンネルダイオードに幾何学的電場集中効果を応用することで実現できることを解析的に示した。

  11. 樹脂窓領域を利用した電子デバイスの波長選択熱放射冷却

    清水信

    2016年10月 ~ 2017年9月

  12. 高温フォトニクスを用いた高度太陽エネルギー利用

    湯上浩雄、井口史匡、清水信

    2011年10月 ~ 2017年3月

  13. 熱放射スペクトル制御素子の高温時赤外放射抑制による高性能エネルギーデバイスの実現

    清水 信

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)

    研究種目:Grant-in-Aid for Young Scientists (B)

    研究機関:Tohoku University

    2014年4月1日 ~ 2016年3月31日

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    本研究は高温下における熱ふく射スペクトル制御デバイスの特に赤外域の放射率に着目し、高温下においても高い波長選択放射性能を持つデバイス作製を目的に研究を行った。具体的な成果としては主に以下の4点である。 (1) 高融点金属材料における高温での酸化状態等を考慮した熱ふく射スペクトル制御デバイスのための基本的知見の体系化、(2) Ni基超合金における波長選択性能低下抑制メカニズム解明、(3) Ni基超合金における知見に基づいた、より高い波長選択性を有する金属―誘電体多層膜構造において詳細特性解明および実性能の検証、(4)金属―誘電体多層膜構造において高い熱安定性能を有することを明らかにした。

  14. 耐熱超合金の自己組織化によるバルク3次元フォトニック結晶創製

    清水 信

    2011年 ~ 2012年

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    本研究の目的はエネルギーシステムの高効率化を目的とした熱輻射スペクトル制御デバイスのためのバルク耐熱金属における周期的微細構造大面積作製技術の確立である。耐熱金属は加工が難しく、既存の微細構造作製技術では大面積作製が難しい。それに代用し得る大面積作製技術として、本研究では金属の自己組織化を用いたバルク3次元フォトニック結晶の作製に関する基盤技術に関して研究を行ってきた。 最終年度の研究計画は組織形態のコントロールによる3次元構造の作製および研究成果のまとめとなる学位論文の執筆である。3次元構造作製のためには深さ方向へのエッチングと構造不均一性の解消という二つの課題を解決する必要があった。深さ方向へエッチングを進めるためには異方性エッチングが必要であり、今回はウェットエッチングとFAB加工を組み合わせてエッチングを行った。具体的にはウェットエッチングで表面に2次元周期的微細構造を作製した後、FAB加工によって構造の床部分をエッチングし、さらに2層目をウェットエッチングするという方法で加工を行った。その結果、表層だけではなく、2層目以降も選択的にエッチングが可能であることが示唆された。この加工を精度良く行うためには分離組織の均一性が重要であると考えられる。自己組織化による2層分離組織を利用するため、半導体作製プロセス等によって作製された構造と比較すると、構造サイズ、分布のばらつきが生じてしまうが、数値計算によりそれらの標準偏差を求め、熱処理条件を変化させることで均一化を行った。その結果、時効熱処理を2回行うことで構造サイズの不均一性が抑制され理論値と同等のものが得られるという結果が示唆された。以上、得られた結果はバルク金属3次元フォトニック結晶作製法の基盤技術として重要な成果である。この技術を用いることでエネルギーシステムの高効率化に向けた多様な熱輸送の制御方法が達成できると考えている。

︎全件表示 ︎最初の5件までを表示