[1] Sungkyunkwan Univ, Dept Phys, Suwon 440746, South Korea
[2] Sungkyunkwan Univ, Dept Energy Sci, Suwon 440746, South Korea
[3] Korea Res Inst Chem Technol, Thin Film Mat Res Grp, Taejon 305600, South Korea
[4] Korea Basic Sci Inst, Div Mat Sci, Taejon 305333, South Korea