Research Objective is regarding understanding materials properties as a function of size, fundamental scientific phenomena at a nanoscale by single species spectroscopy and tailoring materials of desirable properties at the smallest scale. Research works have been focused on synthesis and electrical and optical characterizations of low dimensional materials such as electronic molecules, semiconductor quantum dots and metal nanoparticles (0-D), carbon nanotubes and nanowires(1-D), and thin films(2-D) by a SPM combined with a scanning laser spectroscope. As the feature size in micro/nanoelectronic devices continues to decrease, researches on ultimate electronic materials (molecules) and molecular scale integration (MSI) are needed. We study electrical properties and transport phenomena of individual molecules or their chemical structures. Our group also realizes the electrical and optical devices with low dimensional materials such as CNT-FED, Plastic Solar Cell, OLED, Laser Diode, Solid State Lighting, Organic Thin Film Transistors (OTFTs) for the better life of human being.

• Ph.D. Physical Chemistry, Harvard University, USA, 1993
• M.S. Physical Chemistry, Seoul National University, Korea, 1986
• B.S. Chemistry, Seoul National University, Korea, 1984

1. “High-Power Genuine Ultraviolet Light-Emitting Diodes Based On Colloidal Nanocrystal Quantum Dots.” Nano Lett., 2015, 15 (6), 3793–3799, also reported in C&E News in May 27, 2015.
2. “R/G/B/Natural White Light Thin Colloidal Quantum Dot-Based Light-Emitting Devices.”
3. Adv. Mater, 2014, 26, 6387-6393.
4. “Highly Efficient Cadmium-Free QD Light-Emitting Diodes Enabled by the Direct Formation of Excitons within InP@ZnSeS Quantum Dots.” ACS Nano, 2013, 7 (10), 9019–9026
5. “Bright and Efficient Full-Color Colloidal Quantum Dot Light-Emitting Diodes Using an Inverted Device Structure.” Nano Letters, 2012, 12(5), 2362-2366. Also reported in C&E News in April 10, 2012 and in British PHYSORG.com in April 20, 2012.
6. “Multicolored Light-Emitting Diodes Based on All-QD Multilayer Films Using LbL Assembly Method.” Nano Letters, 2010, 10(7), 2368-2373 (Highlighted in MRS Bulletin, Aug, 2010, 35, p566).
7. “Highly Efficient Green Light-Emitting Diodes Based on CdSe@ZnS Quantum Dots with Chemical Composition Gradient.” Adv. Mater. 2009, 21, 1690-1694. (Highlighted in Nature Journal).