Sung-Jei Hong received his B.S. and M.S. degrees in metallurgical engineering from Sungkyunkwan University, Suwon, Korea in 1991 and 1993, respectively, and his Ph.D. degree in materials engineering from Tohoku University, Sendai, Japan in 2006. After 1993, he joined the Korea Electronics Technology Institute (KETI), Gyeonggi, Korea, where he is currently a Principal Researcher in the Display Research Center Division. His current research interests include semiconductor devices including gas sensors, the design and synthesis of nanoparticles such as copper, silver, nickel, copper–silver core–shell, iron oxide, nickel oxide, tin oxide, indium tin oxide, yttrium oxide, and flexible display, etc. Dr. Hong is a member of the Korean Society of Clean Technology, the Korean Institute of Electrical and Electronic Material Engineers, and the Korea Nanotechnology Research Society.