Chief Scientist Laboratories Quantum Optodevice Laboratory
Chief Scientist: Hideki Hirayama (D.Eng.)
Research Summary

The development of new-frequency semiconductor light sources, such as deep-ultraviolet (DUV) light-emitting diodes (LEDs) and laser diodes (LDs) or terahertz quantum-cascade lasers (THz-QCLs) is one of the most important subjects, because they are strongly required for a wide variety of potential applications, e.g. sterilization, water and air purification, medicine and biochemistry, light sources for high density optical recording, white light illumination and non-destructive see-through examinations. The Quantum Optodevice Laboratory's research is at the forefront of optics and nanotechnology, e.g. in creating innovative optical devices, including undeveloped frequency semiconductor emitters, and in developing a new research field through merging advanced optical/laser science, atomic/nano-scale material fabrication technology, novel semiconductor crystal growth technologies, and so forth. Through the introduction of novel crystal growth technology for wide-gap semiconductors, we have achieved innovative emitting devices such as highly efficient DUV-LEDs with the shortest wavelength regime (220-350nm), or THz-QCLs. We have also investigated the performance limits of these devices by introducing innovative quantum heterostructures and/or photonic nano-structures. Through the creation of the applicable field of these new emitting devices, we aim to contribute to the realization of a richer human society.
Main Research Fields
- Engineering
Related Research Fields
- Interdisciplinary Science & Engineering
- Electron device, Electronic equipment
- Optical engineering, Photon science
Keywords
- DUV-LEDs
- Nitride Semiconductors
- Quantum cascade laser
- Crystal growth
- Inter-subband transition
Selected Publications
- 1.
M. A. Khan, M. Muta, K. Fujimoto, J. G. Rojas, P. Fredes, E. Gramsch, Y. Iwaisako, H. Yaguchi, and H. Hirayama.:
"Estimation of junction temperature in single 228 nm-band AlGaN far-ultraviolet-C light-emitting diode on c-sapphire having 1.8 mW power and 0.32% external quantum efficiency"
physica status solidi (a), 2400064,(2024). - 2.
S. Li, X. Liang, P. Shao, S. Chen, Z. Li, X. Su, T. Tao, Z. Xie, M. A. Khan, L. Wang, T. T. Lin, H. Hirayama, B. Liu, D. Chen, K. Wang, R .Zhang.:
"Monolayer-scale AlN/GaN digital alloys grown by plasma-assisted molecular beam epitaxy"
Applied Physics Letters, Vol. 125, No. 11, (2024). - 3.
H. Murotani, K. Himeno, H. Ohkawara, K. Tani, S. Kurai, N. Okada, N. Maeda, M. A. Khan, H. Hirayama, and Y. Yamada
"Photoluminescence excitation spectroscopy of stimulated emission from AlGaN-based multiple quantum wells with an emission wavelength around 280 nm"
physica status solidi (b), 2400020, (2024). - 4.
A. Ibanez, M. Leroux, N. Nikitskiy, W. Desrat, M. Moret, P. Valvin, G. Cassabois, J. Brault, B. Gil, F. Chugenji, K. Taiga, M. A. Khan, and H. Hirayama.:
"The influence of alloy disorder effects on the anisotropy of emission diagrams in (Al, Ga) N quantum wells embedded into AlN barriers"
physica status solidi (b), 2400215, (2024). - 5.
M. A. Khan, Y. Yamada, and H. Hirayama.:
"Progress and outlook of 10% efficient AlGaN-based (290–310 nm) band UVB LEDs"
physica status solidi (a), 2300581, (2024). - 6.
L. Wang and H. Hirayama
Far-infrared gallium nitride-based quantum cascade laser"
Nanoelectronics Devices: Design, Materials, and Applications-Part II, Bentham Science Publishers, pp. 280-321, (2023). - 7.
K. Nagamatsu, T. Miyagawa, A. Tomita, H. Hirayama, Y. Takashima, and Y. Naoi.:
"High growth temperature for AlN by jet stream gas flow metalorganic vapor phase epitaxy"
Scientific Reports, Vol. 13, No. 1, p. 2438, (2023).
Recent Research Results
Annual research report
Related Links
Lab Members
Principal investigator
- Hideki Hirayama
- Chief Scientist
Core members
- Muhammad Ajmal Khan
- Research Scientist
- Amina Yasin
- Research Scientist
- Muhammad Nawaz Sharif
- Special Postdoctoral Researcher
- Hiromitsu Sakai
- Visiting Scientist
- Eriko Matsuura
- Visiting Technician
- Kenji Yamazawa
- Special Temporary Research Scientist
- Takashi Nishimoto
- Consultant
- Yukio Kashima
- Research Consultant
- Hamida Zia
- Student Trainee
- Yuya Nagata
- Student Trainee
- Kohei Fujimoto
- Student Trainee
- Akira Kaneko
- Student Trainee
- Airu Takahashi
- Student Trainee
- Arata Sasaki
- Student Trainee
- Koki Yabe
- Student Trainee
Contact Information
Cooperation Center, W514
2-1 Hirosawa, Wako, Saitama 351-0198, Japan
Tel: +81-(0)48-467-9387
Fax: +81-(0)48-462-4647
Email: hirayama@riken.jp