[1] Inha Univ, Dept Mat Sci & Engn, Incheon 402751, South Korea
[2] Korea Univ, Sch Elect Engn, Seoul 136701, South Korea
[3] Sungkyunkwan Univ, Sch Adv Mat Sci & Engn, Suwon 16419, South Korea
[4] Inha Univ, Dept Phys, Incheon 402751, South Korea
[5] Natl NanoFab Ctr NNFC, Daejon 34141, South Korea
[6] The Bondis, Hwaseong 18449, South Korea
[7] Hanyang Univ, Div Mat Sci & Engn, Seoul 04763, South Korea