Academic Experiences
• 1990 : B.S. Department of Physics, Seoul National University
• 1992 : M.S. Department of Physics, Seoul National University
• 1998 : Ph.D. Department of Physics, Arizona State University
• 1998-2001 : Post Doctoral Researcher, Solid state division, Oak Ridge National Laboratory
• 2001-2004 : Senior Researcher, AE-Center, Samsung Advanced Institute of Technology
• 2004-2009 : Assistant Professor. Department of Materials Science and Engineering, Seoul National University
• 2009-2013 : Associate Professor. Department of Materials Science and Engineering, Seoul National University
• 2013 – : Professor. Department of Materials Science and Engineering, Seoul National University
Research Interests
• Crystal Structure
– Analyzing crystal structure through (scanning) transmission electron microscopy((S)TEM), convergent beam electron diffraction(CBED) and nano-area electron diffraction(NED).
– Atomic structure of materials and interface, grain boundary, defect structure.
• Electronic Structure
– Analyzing electronic structure of the materials through electron energy loss spectroscopy(EELS) and density functional theory(DFT) calculation.
– Electronic structure of interface, grain boundary and defects.
• Nano scale measurement of charge distribution and stress
– Stress measurement, with 10nm resolution and 0.05% accuracy, of nano-structure’s domain.
– Measuring stress variance with respect to its position in semiconductor device, Stress measurement in multi layered nano thin film.
• In-situ I-V measurement in TEM
– I-V measurement in TEM with in-situ scanning tunneling microscopy(STM)/TEM double tilt holder.
– Direct measurement of local conductivity in nanomaterials, interface, grain boundary, and defect.
Selected Publications
– Direct observation of d-orbital holes and Cu-Cu bonding in Cu2O, Nature, 401,49 (1999)
– High-frequency micromechanical resonators from aluminium-carbon nanotube nanolaminates, Nat. Mater., 7, 457 (2008)
– Electron energy-loss spectroscopy analysis of HfO2 dielectric films on strained and relaxed SiGe/Si substrates, Appl. Phys. Lett., 92, 232906 (2008)
– Atomic structure of conducting nanofilaments in TiO2 resistive switching memory, Nat. Nanotechnol., 5, 148 (2010)
– Nearly single-crystalline GaN light-emitting diodes on amorphous glass substrates, Nat. Photonics, 5, 763 (2011)