Energy is an indispensable part of our lives. Many scientists and engineers in the world are trying to develop many and different types of devices for energy saving and clean energy generation. Semiconductor technologies can contribute to developing those energy-saving & -generation devices. Energy Conversion Devices and Materials (ECO Devices) Laboratory at KAUST is focusing on the development of efficient novel light emitters and clean-energy generation systems using photocatalytic phenomena. The former devices are based on MOCVD technology and material sciences. The later system is mainly nitride photocatalyst invented by Ohkawa in 2001. The topic of this seminar is the former one.
The three primary colors in light are RGB. Green and blue LEDs have been realized by using InGaN active region. The current red LEDs are based on AlGaAs or InGaP as the active region. If we can realize red LEDs by InGaN, it is possible to integrate RGB LEDs in a wafer. Such RGB integration is a breakthrough to develop the next displays, so-called, micro-LED displays that are the next after the OLED displays, and functional LED lightings. In this seminar, the science of MOCVD, the material science of InGaN, and the new-born InGaN-based red LED performance will be discussed.
Kazuhiro Ohkawa is a professor of Electrical Engineering, Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) division at King Abdullah University of Science and Technology (KAUST). Principle investigator of Energy Conversion Devices and Materials (ECO Devices) lab at KAUST. He is a Fellow of Japan Society of Applied Physics. Before joining KAUST, he was a professor of Applied Physics at Tokyo University of Science in Japan, a professor (lifelong title) of Physics at the University of Bremen in Germany, and a senior research staff at Panasonic. He is interested in optical devices such as LEDs, laser diodes, and photocatalysts. He is familiar with wide-bandgap materials (III-Nitrides and II-VI compounds) and thin-film growth technologies (MOCVD and MBE). He invented the current n- & p-doping technologies for II-VI materials by Cl and nitrogen plasma, respectively. The nitrogen plasma became a standard in MBE for nitride semiconductors. He developed a simulation technology to understand nitride MOCVD. Many industries in Japan and Europe have introduced that simulation already. Recent popular nitride photocatalyst is also his invention. His recent interest is the development of red InGaN-base LEDs, which may have significant impacts on micro-LED displays and functional lightings.