1. Research Institute, Force4 Corp., Daechon-dong, Buk-gu,
Gwangju, 500-470 Republic of Korea
2. Department of Chemistry, Korea University, Seoul, 136-706 Republic
of Korea
3. School
of Materials
Science and Engineering, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju, 500-757
Republic of Korea