1. Institute of Solar Energy Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy Shanghai Jiao Tong University Shanghai 200240 P. R. China
2. Risen (Changzhou) New Energy Co., Ltd Jiangsu 213200 P. R. China
3. Research School of Electrical, Energy and Materials Engineering Australian National University Canberra ACT 0200 Australia
4. Collaborative Innovation Center of Advanced Microstructures Nanjing 210093 P. R. China