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, N. Maeda, H. Rangaraju, M. Jo, K. Iimura, and H. Hirayama.:
"Efficiency droop in AlGaN crystal-based UVB LEDs in the context of electron blocking mechanism"
Journal of Crystal Growth, Vol. 604, p. 127032, (2023). - 2.
M. A. Khan, N. Maeda, Y. Itokazu, M. Jo, K. Iimura, and H. Hirayama.:
"Milliwatt Power AlGaN Deep-UV Light-Emitting Diodes at 254 nm Emission as a Clean Alternative to Mercury Deep-UV Lamps"
physica status solidi (a), Vol. 220, No. 1, p. 2200621, (2023). - 3.
Y. Itokazu, N. Maeda, H. Yaguchi, and H. Hirayama.:
"Significant improvement of injection efficiency in deep-UV LD structures by light Mg doping in p-core layer"
Japanese Journal of Applied Physics, Vol. 62, p. SC1091, (2023). - 4.
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). - 5.
M. A. Khan, Y. Itokazu, N. Maeda, M. Jo and H. Hirayama.:
"Realization of high injection current density up to 200 kA/cm-2 in electrically pumped AlGaN ultraviolet laser diodes on c-sapphire substrate"
Optical Materials, 133, 112927, (2022). - 6.
M. A. Khan, N. Maeda, J. Yun, M. Jo, Y. Yamada, and H. Hirayama.:
"Achieving 9.6% Efficiency in 304 nm p-AlGaN UVB LED via Increasing the Holes Injection and Light Reflectance"
Scientific Reports 12 (1), 1-11, (2022). - 7.
M. A. Khan, N. Maeda, M. Jo, Y. Yamada, and H. Hirayama.:
"Highly Transparent p-AlGaN-Based (326-341 nm)-Band Ultraviolet-A Light-Emitting Diodes on AlN Templates: Recent Advances and Perspectives"
Physica Status Solidi A, Vol. 219, No. 7, p. 2100605, (2022). - 8.
H. Murotani, Y. Yamada, and H. Hirayama.:
"Excitonic optical properties of deep-UV luminescent AlGaN"
JSAP Review, 220405, September 1, (2022). 10.11470/jsaprev.220405 - 9.
S. Tsuda, T. Miyagawa, R. Aono, H. Hirayama, Y. Takashima, and Y. Naoi.:
"Reduction of parasitic reaction in high-temperature AlN growth by jet stream gas flow metal-organic vapor phase epitaxy"
Scientific Reports 12 (1), 1-7, (2022).
Recent Research Results
Annual research report
Related Links
Lab Members
Principal investigator
- Hideki Hirayama
- Chief Scientist
Core members
- Muhammad Ajmal Khan
- Research Scientist
- Yukio Kashima
- Technical Staff II
- Eriko Matsuura
- Visiting Technician
- Noritoshi Maeda
- Research Consultant
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 [at] riken.jp