Dr. Hahn is Fellow of Korea Academy of Science and Technology, Fellow of the American Ceramic Society, Director of BK21 Center for Future Energy Materials and Devices, Director of National Leading Research Lab, and Head of Graduate 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 under Professor Hong Yong Sohn's supervision. Dr. Hahn developed the world’s first computational simulation tool for the analysis of the copper production Outokumpu Flash Smelting Process during his Ph.D. program. The achievement was recognized and awarded the 'Extractive Metallurgy Best Science Award' by the Minerals, Metals and Materials (TMS) in 1990. His main research interest is the synthesis of metal, metal oxide, graphene-based composites and ceramic nanostructures and their applications for solar cells, optoelectronic devices and chemical and biological sensors.

Dr. Hahn has been successful during the 28 years he has worked as a professional investigator. His professional accomplishments have been quite impressive with publication of over 292 peer-reviewed SCI papers with 10,599 citations and high H-index (currently 52 by Google Scholar) and 15 registered patents. He also co-authored/co-edited 7 books including the world first multivolume handbook, Metal Oxide Nanostructures and Their Applications (5 volume set) published in 2010 by American Scientific Publishers, which covered a wide variety of advanced research and developments in the field of metal oxide nanomaterials and their applications.

Dr. Hahn received Woo Seong-Il Materials Award in 2018, conferred by the Korean Institute of Chemical Engineers, Asian Energy Technology Award in 2017, conferred by International Association of Advanced materials (IAAM, Sweden), Rudolph A. Marcus Award in 2016, conferred by Science Advances Today, ACerS Global Ambassador Award in 2016, the Scientist of Month Award in 2011 conferred by Korea Ministry of Education, Science and Technology, and the CBNU’s Best Research Professor Award consecutively in 2008-2010. He also honored as Top 100 Scientists four times in 2005 2011, 2014 and 2015 accredited by International Biographical Center, Cambridge, UK.

Dr. Hahn, now acting as a Global Ambassador for the ACerS since 2016, has also made huge contributions to the international ceramic community: he has served as a lead chair of Materials Challenges in Alternative and Renewable Energy (MCARE) for 2015 and 2017, and co-chair of MCARE for 2016 and 2018; co-organized over 18 symposia, workshops and conferences on ceramic and related materials, including a very popular series of symposia on Functional Nanomaterials and Thin Films for Sustainable Energy Harvesting, Environmental and Health Applications since 2010 at the Daytona Beach annual meeting of the American Ceramic Society. He also delivered numerous Keynote and Invited talks at international ceramic society meetings.