Professor Hahn is Fellow of the Korea Academy of Science and Technology, Fellow of the American Ceramic Society, Director of BK21 Center for Future Energy Materials and Devices, and Head of School of Semiconductor and Chemical Engineering, Chonbuk National University (CBNU). He joined CBNU in 1991, prior to which he worked for LG Metals Research Center for 1988-1991 after he received his Ph.D. in Metallurgical Engineering from University of Utah in 1988. His research interest is synthesis of metal and metal oxide nanostructures and their applications for optoelectronic devices and chemical and biological sensors, resulting in over 290 peer-reviewed SCI papers and 15 patents. He co-authored 6 books including Metal Oxide Nanostructures and Their Applications (5 volume sets) published by American Scientific Publishers in 2010. He received Woo SeongIl Materials Awards 2018 by KIChE, Asian Energy Technology Award 2017 by International Association of Advanced Materials, Rudolf A. Marcus Award for outstanding research in the area of chemical science in 2016, the American Ceramic Society Global Ambassador Award 2016, the Scientist of the Month Award in 2011 by Korea Ministry of Education, Science and Technology, the CBNU’s Best Research Professor Award consecutively in 2008-2010, and Top 100 Scientists Award four times in 2005, 2011, 2014 and 2015 accredited by International Biographical Center, Cambridge, UK.