a
Dept. of BIN Fusion Technology, Chonbuk National University, 567 Baekje-daero, Jeonju 561-756, Republic of Korea
b
School of Semiconductor and Chemical Engineering, and Semiconductor Physics Research Center, Chonbuk National University, 567 Baekje-daero, Jeonju 561-756, Republic of Korea
E-mail: ybhahn@chonbuk.ac.kr