Present, Faculty, School of Elec. Eng. & Com. Sci., GIST. 2014 ~ 2015, Visiting Prof., Caltech, USA. 2013 ~ Present, Science & Creativity Ambassador" designated by Korean Foundation for the Advancement of Science and Creativity. 2012 ~ Present, selected into Marquis who’s who. 2004 ~ 2007, Assistant Scientist, Univ. of Florida, USA. 2003 ~ 2004, Visiting Postdoctoral Associate (as part of an army service), Seoul Nat'l Univ. 2002 ~ 2003, Postdoctoral Associate, National High Magnetic Field Lab., USA. 2001 ~ Present, Awards from 2001 CLEO-PR (Conference Travel Award for Students), 2005 NSF research highlight from NHMFL, 2011 KPS/2010 OSK/2012 Int. Conf. on Nano Sci. & Tech./2015 CLEO-PR(Best conf. papers), 2016 GIST research excellence & 10 most representative technologies.  

Heat-smart optoelectronics: Heat dissipation engineering in semiconductor chips. - Thermoelectricity using semiconductors: Waste heat recovery into electricity. - Quantum phononics: Quantized thermal conduction and terahertz energy transport. - Thermal metamaterials: Design, growth, and characterizations - Electro-phononics for thermal circuitry - Integration of electronics, photonics, and phononics.