[1] Univ Kebangsaan Malaysia, SERI, Bangi 43600, Selangor, Malaysia
[2] Univ Technol Sydney, Ctr Clean Energy Technol, Sch Math & Phys Sci, Sydney, NSW 2007, Australia
[3] Univ Kebangsaan Malaysia, Fac Sci & Technol, Sch Phys, Bangi 43600, Selangor, Malaysia
[4] Univ Kebangsaan Malaysia, Fac Sci & Technol, Ctr Frontier Sci, Bangi 43600, Selangor, Malaysia
[5] Xi An Jiao Tong Univ, Minist Educ, Sch Elect & Informat Engn, Elect Mat Res Lab,Key Lab, Xian 710049, Peoples R China
[6] Xi An Jiao Tong Univ, Int Ctr Dielect Res, Sch Elect & Informat Engn, Xian 710049, Peoples R China
[7] Loughborough Univ, Dept Chem, ERL, Loughborough LE11 3TU, Leics, England