1. College of Physics and Energy, Fujian Normal University, Fuzhou 350117, P. R. China
2. Fujian Provincial Key Laboratory of Quantum Manipulation and New Energy Materials, Fuzhou 350117, P. R. China
3. Fujian Provincial Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Xiamen 361005, P. R. China
4. Fujian Provincial Engineering Technology Research Center of Solar Energy Conversion and Energy Storage, Fuzhou 350117, China
5. Hefei National Laboratory for Physical Science at the Microscale, University of Science and Technology of China, Hefei 230026, Anhui, P. R. China
6. Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore