Professor Ohkawa is a highly regarded researcher, widely recognized for his contributions to electrical engineering and applied physics, particularly for his pioneering work in refining the metalorganic vapor-phase epitaxy technique for novel wide bandgap semiconductors.
Biography
Kazuhiro Ohkawa is a professor of Electrical and Computer Engineering (ECE) Program and the principal investigator of the Energy Conversion Devices and Materials (ECO Devices) Laboratory at KAUST.
Before joining the University, he was a senior research member at Panasonic Ltd, a professor of Physics at the University of Bremen, Germany and a professor of Applied Physics at Tokyo University of Science, Japan.
Professor Ohkawa invented nitrogen-plasma doping for ZnSe and their blue-green lasers and LEDs. The nitrogen-plasma source is now a standard nitride molecular beam epitaxy (MBE) technology. He later became involved in the metalorganic vapor-phase epitaxy (MOVPE) growth of GaN, where he developed world-record deep-red indium gallium nitride (InGaN) LEDs based on the original MOVPE technique. His nitride MOVPE simulations have contributed to industries worldwide that produce InGaN LEDs, lasers and AlGaN electronics. Additionally, he invented nitride photocatalysts, which are instrumental in solar hydrogen production and artificial photosynthesis.
He has received numerous honors and recognitions for his contributions to optoelectronics, including being named an honorary professor (lifelong) at the University of Bremen, Germany; visiting professor at Mie University, Japan; guest professor at Xiamen University, China; and visiting professor (lifelong) at Tianjin University of Technology and Education, China. He is a fellow of the Japan Society of Applied Physics. Approximately 20 companies have sought his consulting expertise in these research areas.
His research has led to over 200 scientific publications, 28 granted US and Japanese patents and more than 70 invited talks.
Research Interests
Professor Ohkawa’s research at KAUST focuses on applying energy-conversion phenomena towards a more sustainable future. The highly regarded researcher’s contributions to applied physics and optoelectronics have resulted in his technologies being adopted by many companies and institutions worldwide.
Three notable contributions include the first doping technologies for II-VI compounds to realize n- and p-types. Notably, the nitrogen plasma source for the p-type has become the standard technology for molecular-beam epitaxy growth of nitride semiconductors. The second is MOCVD technology for nitride semiconductors. The technology has developed InGaN-based RGB full-color LEDs and made it possible to study MOCVD reactors scientifically. The third is the invention of a nitride photocatalyst for water splitting and artificial photosynthesis.
Ohkawa is also the principal investigator of the ECO Devices Laboratory. The lab’s research topics are not only monolithic RGB micro-LEDs but also applications of those micro-LEDs for high-speed visible light communications (so-called "Li-Fi") and vertical-cavity surface-emitting lasers (VCSELs). RGB VCSELs will enable ultimate laser-based head-mounted displays.
Awards and Distinctions
- Honorary Professor (lifelong), University of Bremen (Germany), 2024
Education
- Doctor of Philosophy (Ph.D.)
- Science, University of Tokyo, Japan, 1992
- Master of Science (M.S.)
- Physics, University of Tokyo, Japan, 1985
- Bachelor of Science (B.S.)
- Physics, Tokyo University of Science, Japan, 1983
Quote
“Our group is developing novel micro-LEDs and VCSELs based on material science and semiconductor epitaxy. These are the crucial devices for micro-LED displays or laser-drawing displays on the retina. These displays will save a lot of energy and are useful for AR and VR. Let's change the energy and digital sections of the future world together.”
Patents
Photoelectrode used for carbon dioxide reduction and method for reducing carbon dioxide using the photoelectrode
Patent number: 9551077
Light emitting ceramic substrate including group-III nitride
Patent number: 9373687
Photoelectrode Used for Carbon Dioxide Reduction and Method for Reducing Carbon Dioxide Using the Photoelectrode
Publication number: 20140360883
More patents by Professor Ohkawa
Carbon Dioxide Reduction Device and Method for Reducing Carbon Dioxide
Publication number: 20150218719
Questions and Answers
Why KAUST?
I knew KAUST from a Nobel laureate during the Nobel week in Stockholm. I joined KAUST in 2016 as the Director of the Energy Conversion Devices and Materials (ECO Devices) Lab. I recognized that KAUST creates a scientific atmosphere to realize something new. Thanks to such situations, I aim to develop new valuable devices and cutting-edge semiconductor growth methods.
What are the main challenges of micro-LEDs research?
When decreasing the chip size the effect of the sidewalls of a semiconductor chip strongly influences the efficiency. The surface has different physics compared to solid-state materials. That is a kind of singular plane. A part of the injected current is lost on the surface, resulting in lower efficiency. We can fabricate high-quality surfaces based on epitaxy, device fabrication, and surface treatment. Recently, we invented the hydrogen passivation method to form pixels without introducing surfaces. Then, we have achieved the world-top-class red micro-LEDs. If you want to know more about micro-LEDs research, please come to my office.