1. Department of Materials Science and Engineering; Shenzhen Key Laboratory of Full Spectral Solar Electricity Generation (FSSEG); Southern University of Science and Technology (SUSTech); No. 1088, Xueyuan Rd Shenzhen 518055 Guangdong P. R. China
2. Department of Physics; The University of Hong Kong; Pokfulam Hong Kong SAR
3. Department of Physics; Southern University of Science and Technology (SUSTech); No. 1088, Xueyuan Rd Shenzhen 518055 Guangdong P. R. China