1. Nano Electronics Laboratory, Samsung Advanced Institute of Technology, Suwon, Gyeonggi-do 443-803, South Korea
2. Research Center for Time-Domain Nano-functional Devices, Samsung Advanced Institute of Technology, Suwon, Gyeonggi 443-803, South Korea
3. Department of Electrical Engineering, Korea University, Anam-dong, Seongbuk-gu, Seoul 136-713, South Korea
4. CAE Group, Platform Technology Laboratory, Samsung Advanced Institute of Technology, Suwon, Gyeonggi-do 443-803, South Korea
5. Organic Material Lab, Samsung Advanced Institute of Technology, Suwon, Gyeonggi-do 443-803, South Korea
6. School of Integrative Engineering, Chung-Ang University, Seoul 156-756, South Korea
7. Department of Chemical and Biological Engineering, Gachon University, Seongnam, Gyeonggi-do 461-701, South Korea