Prof. Hideki Hirayama Profile

Prof. Hideki Hirayama

Chief Scientist at RIKEN

SPIE Involvement:

Conference Program Committee | Author

Publications (20)

Proceedings Article | 5 October 2023 Presentation

Progress in 230nm-band AlGaN far-UVC LEDs and demonstration of 100mW class LED panels

Hideki Hirayama

Proceedings Volume PC12652, PC1265207 (2023) https://doi.org/10.1117/12.2677368

KEYWORDS: Aluminum gallium nitride, Light sources, Continuous wave operation, Light emitting diodes, External quantum efficiency, Polarization, Lenses, Quartz, Ceramics, Doping

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Proceedings Article | 5 March 2022 Poster

Improvement of crystal orientation in AlN with controlled inversion domain

Shota Tsuda, Takumi Miyagawa, Reiya Aono, Atsushi Tomita, Hideki Hirayama, Yuusuke Takashima, Yoshiki Naoi, Kentaro Nagamatsu

Proceedings Volume PC12001, PC120011C (2022) https://doi.org/10.1117/12.2607577

KEYWORDS: Diffraction, Light emitting diodes, Deep ultraviolet, Polarization, X-rays, Diffusion, Oxygen, Ultraviolet light emitting diodes, Sapphire, Aluminum nitride

Proceedings Article | 5 March 2022 Poster

Threshold temperature in annihilation radius of dislocation for AlN

Shota Tsuda, Takumi Miyagawa, Reiya Aono, Atsushi Tomita, Hideki Hirayama, Yuusuke Takashima, Yoshiki Naoi, Kentaro Nagamatsu

Proceedings Volume PC12001, PC120011B (2022) https://doi.org/10.1117/12.2607569

KEYWORDS: Light emitting diodes, X-rays, Interfaces, Ultraviolet light emitting diodes, Gallium nitride, Sapphire, Aluminum, Aluminum nitride, Luminous efficiency, Vapor phase epitaxy

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Proceedings Article | 11 October 2021 Presentation

High injection current density via Al-graded undoped-AlGaN cladding layer and Al-graded p-AlGaN hole source layer in AlGaN UVB LDs

Muhammad Ajml Khan, Noritoshi Maeda, Yuri Itokazu, Masafumi Jo, Hideki Hirayama

Proceedings Volume 11891, 118910E (2021) https://doi.org/10.1117/12.2603964

KEYWORDS: Mirrors, Deep ultraviolet, Cladding, Metals, Semiconductor lasers, Aluminum nitride, Plasma etching, Optical pumping, Plasma, RGB color model

Proceedings Article | 5 March 2021 Presentation

High-power AlGaN UVC LEDs using PhC reflector p-contact layers

Hideki Hirayama, Yukio Kashima, Eriko Matsuura, Noritoshi Maeda, Masafumi Jo, Yasushi Iwaisako, Takeshi Iwai, Mitsunori Kokubo, Takaharu Tashiro, Kanji Furuta, Ryuichiro Kamimura, Tamato Osada, Hideki Takagi, Yuuichi Kurashima, Tsugumu Nagano

Proceedings Volume 11686, 116860X (2021) https://doi.org/10.1117/12.2579591

KEYWORDS: Reflectors, Light emitting diodes, External quantum efficiency, Resistance, Photonic crystals, Absorption

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Proceedings Article | 5 March 2021 Presentation

Progress on high-power UVC LEDs by increasing light-extraction efficiency

Hideki Hirayama, Yukio Kashima, Eriko Matsuura, Noritoshi Maeda, Masafumi Jo

Proceedings Volume 11706, 117060G (2021) https://doi.org/10.1117/12.2579593

KEYWORDS: Reflectors, Light emitting diodes, External quantum efficiency, Resistance, Photonic crystals, Absorption

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Proceedings Article | 1 April 2020 Presentation + Paper

AlGaN metasurface to increase the light-extraction efficiency of deep ultraviolet light-emitting diodes by perfect transmittance before critical angle

Joosun Yun, Hideki Hirayama

Proceedings Volume 11344, 1134412 (2020) https://doi.org/10.1117/12.2553047

KEYWORDS: Light emitting diodes, Finite-difference time-domain method, Deep ultraviolet, Transmittance

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Proceedings Article | 9 March 2020 Presentation

Progress in AlGaN UVC LEDs by improving light extraction efficiency (Conference Presentation)

Masafumi Jo, Noritoshi Maeda, Hideki Hirayama

Proceedings Volume 11302, 113021C (2020) https://doi.org/10.1117/12.2543013

KEYWORDS: Light emitting diodes, Finite-difference time-domain method, Ultraviolet radiation, Mercury, Lamps, Photonic crystals, Aluminum nitride, Internal quantum efficiency, Absorption

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Proceedings Article | 5 March 2019 Presentation

LEE enhancement in AlGaN UVC LED using photonic crystal reflector fabricated on p-GaN contact layer (Conference Presentation)

Hideki Hirayama, Yukio Kashima, Yasuhiro Watanabe, Tomohiko Shibata, Noritoshi Maeda, Masafumi Jo, Eriko Matsuura, Takeshi Iwai, Mitsunori Kokubo, Takaharu Tashiro, Kanji Furuta, Ryuichiro Kamimura, Tamato Osada, Hideki Takagi, Yuuichi Kurashima, Yasushi Iwaisako, Tsugumu Nagano

Proceedings Volume 10918, 109181V (2019) https://doi.org/10.1117/12.2505751

KEYWORDS: Reflectors, Light emitting diodes, External quantum efficiency, Resistance, Photonic crystals, Absorption

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Proceedings Article | 19 April 2017 Presentation

Over 10% EQE AlGaN deep-UV LED using transparent p-AlGaN contact layer (Conference Presentation)

Hideki Hirayama, Takayoshi Takano, Jun Sakai, Takuya Mino, Kenji Tsubaki, Noritoshi Maeda, Masafumi Jo, Issei Ohshima, Takuma Matsumoto, Norihiko Kamata

Proceedings Volume 10104, 101041P (2017) https://doi.org/10.1117/12.2254100

KEYWORDS: Quantum wells, Transparency, Light emitting diodes, External quantum efficiency, Deep ultraviolet, Electrodes, Reflectivity, Gallium nitride, Current controlled current source

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Proceedings Article | 31 August 2015 Paper

Recent progress of THz-quantum cascade lasers using nitride-based materials

Hideki Hirayama, Wataru Terashima

Proceedings Volume 9585, 958504 (2015) https://doi.org/10.1117/12.2188109

KEYWORDS: Semiconductors, Quantum wells, Waveguides, Metals, Quantum cascade lasers, Gallium nitride, Sapphire, Terahertz radiation, Phonons, Metalorganic chemical vapor deposition

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Proceedings Article | 13 May 2015 Paper

GaN-based terahertz quantum cascade lasers

Wataru Terashima, Hideki Hirayama

Proceedings Volume 9483, 948304 (2015) https://doi.org/10.1117/12.2184199

KEYWORDS: Semiconductors, FT-IR spectroscopy, Quantum wells, Quantum cascade lasers, Gallium nitride, Sapphire, Terahertz radiation, Phonons, Metalorganic chemical vapor deposition, Laser systems engineering

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Proceedings Article | 10 March 2015 Paper

Recent progress and future prospects of THz quantum-cascade lasers

H. Hirayama, W. Terashima, Tsung-Tse Lin, Miho Sasaki

Proceedings Volume 9382, 938217 (2015) https://doi.org/10.1117/12.2082723

KEYWORDS: Semiconductors, Waveguides, Scattering, Metals, Gallium arsenide, Quantum cascade lasers, Gallium nitride, Terahertz radiation, Aluminum nitride, Phonons

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Proceedings Article | 31 January 2014 Paper

Recent progress toward realizing GaN-based THz quantum cascade laser

H. Hirayama, W. Terashima

Proceedings Volume 8993, 89930G (2014) https://doi.org/10.1117/12.2039214

KEYWORDS: Semiconductors, Surgery, Scattering, Gallium arsenide, Quantum cascade lasers, Electroluminescence, Gallium nitride, Sapphire, Terahertz radiation, Phonons

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Proceedings Article | 27 March 2013 Paper

Intersubband spontaneous emission from GaN-based THz quantum cascade laser

W. Terashima, H. Hirayama

Proceedings Volume 8625, 862516 (2013) https://doi.org/10.1117/12.2003309

KEYWORDS: Fabrication, Semiconductors, Polarization, Scattering, Electrons, Quantum cascade lasers, Electroluminescence, Gallium nitride, Terahertz radiation, Phonons

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Proceedings Article | 27 March 2013 Paper

Development of 260 nm band deep-ultraviolet light emitting diodes on Si substrates

Takuya Mino, Hideki Hirayama, Takayoshi Takano, Kenji Tsubaki, Masakazu Sugiyama

Proceedings Volume 8625, 86251Q (2013) https://doi.org/10.1117/12.2002322

KEYWORDS: Microscopes, Light emitting diodes, External quantum efficiency, Deep ultraviolet, Silicon, Electroluminescence, Scanning electron microscopy, Sapphire, Aluminum nitride, Epitaxial lateral overgrowth

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Proceedings Article | 7 January 2011 Paper

Advances of AlGaN-based high-efficiency deep-UV LEDs

Hideki Hirayama

Proceedings Volume 7987, 79870G (2011) https://doi.org/10.1117/12.888927

KEYWORDS: Electron beam lithography, Quantum wells, Light emitting diodes, External quantum efficiency, Deep ultraviolet, Electrodes, Ultraviolet radiation, Sapphire, Aluminum nitride

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Proceedings Article | 12 February 2010 Paper

Recent progress of 220-280 nm-band AlGaN based deep-UV LEDs

Hideki Hirayama

Proceedings Volume 7617, 76171G (2010) https://doi.org/10.1117/12.845512

KEYWORDS: Quantum wells, Continuous wave operation, Light emitting diodes, External quantum efficiency, Deep ultraviolet, Ultraviolet radiation, Sapphire, Aluminum, Aluminum nitride

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Proceedings Article | 16 February 2009 Paper

222-282 nm AlGaN and InAlGaN based deep-UV LEDs fabricated on high-quality AlN template

Hideki Hirayama, Norimichi Noguchi, Sachie Fujikawa, Jun Norimatsu, Norihiko Kamata, Takayoshi Takano, Kenji Tsubaki

Proceedings Volume 7216, 721621 (2009) https://doi.org/10.1117/12.809729

KEYWORDS: Quantum wells, Continuous wave operation, Light emitting diodes, External quantum efficiency, Deep ultraviolet, Ultraviolet radiation, Electroluminescence, Sapphire, Aluminum nitride

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Proceedings Article | 6 July 2004 Paper

Quaternary InAlGaN-based deep-UV LED with high-Al-content p-type AlGaN

Hideki Hirayama, Yoshinobu Aoyagi

Proceedings Volume 5359, (2004) https://doi.org/10.1117/12.528091

KEYWORDS: Quantum wells, Light emitting diodes, Deep ultraviolet, Ultraviolet radiation, Sapphire, Aluminum, Indium gallium nitride, Silicon carbide, Gallium, Internal quantum efficiency

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