text: * Director Center for Superfunctional Materials (CSM), UNIST (2014–present) 
  * Distinguished Professor of Dept. of Chemistry, UNIST (2014–present)
  * Director of CSM, Pohang University of science and Technology POSTECH (1997-2014)
  * Professor of Dept. of Chemistry at Pohang University of Science & Technology POSTECH (1988-2014)
  * Visiting Scholar, Dept. Elect. Engineering & Nano Center, Columbia University (2004-2005)
  * Visiting Scientist/Professor, Dept. of physics, MIT (1994-1995)
  * Visiting Assistant Professor, Researcher Assistant Professor, Rutgers University (1985-1987)
  * Postdoctoral Researcher Fellow, IBM (1982-1985)
  * Instructor, Assistant professor, Dept. of Physics Chungnam National University. (1975-1978)