1. Multi-Functional Nano/Bio Electronics Laboratory; Sungkyunkwan University; Gyeonggi 16419 South Korea
2. Department of Physics and Atmospheric Science; Dalhousie University; Halifax NS B3H 4R2 Canada
3. Department of Graphic Arts Information Engineering; Pukyong National University; Busan 608-739 South Korea
4. Institute of Advanced Composite Materials; Korea Institute of Science and Technology; Jeonbuk 565-905 South Korea
5. Department of Electrical and Computer Engineering and Waterloo Institute for Nanotechnology (WIN); University of Waterloo; Waterloo ON N2L 3G1 Canada
6. Measurement & Analysis Team; National Nanofab Center; Daejeon 34141 South Korea
7. Department of Applied Physics; Kyung Hee University; Gyeonggi 17104 South Korea