1. School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China
2. Beijing Key Laboratory of Nanophotonics & Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing 100081, China
3. Centre for Micro-Photonics, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Victoria 3122, Australia
4. Department of Physics of Complex Systems, Faculty of Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
5. Australian Centre for Advanced Photovoltaics, School of Photovoltaic and Renewable Energy Engineering, UNSW Sydney, Sydney 2052, Australia