1. Institute for Solar Energy Systems School of Physics Sun Yat‐Sen University Guangzhou 510006 China
2. State Key Laboratory of PV Science and Technology Trina Solar Changzhou 213031 China
3. Global Photovoltaic Joint Innovation Center Aikosolar Yiwu 322009 China
4. Foshan Raynova Materials Technology Co., LTD Foshan 528000 China