1. Experimental Center of Advanced Materials School of Materials Science and Engineering Beijing Institute of Technology Beijing 100081 China
2. Beijing Key Laboratory for Theory and Technology of Advanced Battery Materials Key Laboratory of Polymer Chemistry and Physics of Ministry of Education BIC‐ESAT Department of Materials Science and Engineering College of Materials Science and Engineering Peking University Beijing 100871 China
3. School of Aerospace Engineering Beijing Institute of Technology Beijing 100081 China
4. IEK‐5 Photovoltaik Forschungszentrum Jülich GmbH 52428 Jülich Germany