[1] Sungkyunkwan Univ, Dept Phys, Suwon 440746, South Korea
[2] Sungkyunkwan Univ, Sungkyunkwan Adv Inst Nanotechnol SAINT, Suwon 440746, South Korea
[3] Sungkyunkwan Univ, Sch Mech Engn, Suwon 440746, South Korea
[4] Sungkyunkwan Univ, Dept Energy, Suwon 440746, South Korea
[5] Sungkyunkwan Univ, Sch Elect & Elect Engn, Suwon 440746, South Korea