Yoshitaka Okada received the B.Sc. degree in electronic and electrical engineering from the King's College, University of London, London, U.K., in 1984, and the M.Eng. and Ph.D. degrees in electronic engineering from The University of Tokyo, Tokyo, Japan, in 1987 and 1990, respectively. He is currently a Professor with the Research Center for Advanced Science and Technology (RCAST), The University of Tokyo. From 1987 to 1988, he was a Fulbright Scholar with the University of California, Santa Barbara. In 1990, he joined the Institute of Materials Science, University of Tsukuba, as a Research Assistant. He became an Assistant Professor in 1991, and an Associate Professor with the Institute of Applied Physics, University of Tsukuba, in 2003. In 2008, he moved to RCAST, The University of Tokyo, where he is currently a Professor with the Department of New Energy and Head of Academic-Industrial Joint Laboratory for Renewable Energy. He was appointed as a Visiting Assistant Professor with the Department of Electrical Engineering, Stanford University from 1995 to 1996, as a Visiting Fellow (Japan Society of Promotion of Science-Royal Society Exchange Fellow) with the Department of Physics, Imperial College London in 2006, and as a Visiting Fellow with Clare Hall and Cavendish Laboratory, University of Cambridge in 2015. He has authored and coauthored more than 200 refereed journal publications and more than 230 international conference presentations. His research interests include epitaxial crystal growth of III-V-N dilute nitride semiconductors and low-dimensional quantum nanostructures for applications to high-efficient multijunction and intermediate-band and hot-carrier solar cells. Dr. Okada is a member of the Materials Research Society and Japan Society of Applied Physics (JSAP). He was the recipient of the Siemens Prize from King's College London in 1984 and the Young Researcher Award from JSAP in 1990.