Yong-Duck Chung received his BS, MS, and PhD degrees in physics from Yonsei University, Seoul, Rep. of Korea, in 1995, 1997, and 2002, respectively. In 2002, he joined ETRI, where he is currently a principal researcher. Since 2010, he has also been with the Department of Advanced Devices Technology, Korea University of Science and Technology, Daejeon, Rep. of Korea, where he is a professor. From December 2008 to January 2009, he was a visiting scientist at the University of Delaware, Network, DE, USA, where he studied thin-film solar cell technologies. His research interests include the fabrication and characterization of thin-film photovoltaics devices. He is the author or co-author of more than 95 peer-reviewed papers related to thin films and solar cells. He has been a program committee member of several international conferences and a reviewer of leading journals on solar cells and thin films.