1. Photovoltaic Materials Unit; National Institute for Materials Science; 1-2-1 Sengen Tsukuba Ibaraki 305-0047 Japan
2. Inorganic and Physical Chemistry Division; CSIR-Indian Institute of Chemical Technology; Uppal Road, Tarnaka Hyderabad 500607 India
3. Center of Excellence for Research in Engineering Materials (CEREM); College of Engineering; King Saud University; Riyadh 11421 Saudi Arabia
4. Solar Energy Research Institute (SERI); University Kebangsaan Malaysia (UKM); Bangi 43600 Selangor Darul Ehsan Malaysia