[1] Natl Inst Mat Sci, Photovolta Mat Grp, 1-2-1 Sengen, Tsukuba, Ibaraki 3050047, Japan
[2] Univ Kebangsaan Malaysia, Solar Energy Res Inst, Bangi 43600, Selangor Darul, Malaysia
[3] Nihon Univ, Coll Sci & Technol, Chiyoda Ku, 1-8-14 Kanda Surugadai, Tokyo 1018308, Japan
[4] Univ Tsukuba, Grad Sch Pure & Appl Sci, Tsukuba, Ibaraki 3058573, Japan
[5] Dongguk Univ, Dept Energy & Mat Engn, Seoul 04620, South Korea
[6] Dongguk Univ, Res Ctr Photoenergy Harvesting & Convers Technol, Seoul 04620, South Korea