1. Key Laboratory of Rubber‐Plastics of Ministry of Education/Shandong Province (QUST) School of Polymer Science & Engineering Qingdao University of Science & Technology 53‐Zhengzhou Road Qingdao 266042 P. R. China
2. Hybrid Solar Cells Faculty of Engineering and Natural Sciences Tampere University P.O. Box 541 Tampere FI‐33014 Finland