1. 932, Yun-Tech, ITECO 762, Deokpung-dong, Hanam-si, Gyeonggi-do, Republic of Korea
2. Department of Materials Science and Engineering, CBAS, University of Ghana, Legon, Ghana
3. Division of Semiconductor and Chemical Engineering, Chonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea