A Fluorinated Polythiophene Derivative with Stabilized Backbone Conformation for Highly Efficient Fullerene and Non-Fullerene Polymer Solar Cells

• DOI: 10.1021/acs.macromol.6b00248
• Publication Date: 2016-04-09T01:33:39Z
• Authors: Shaoqing Zhang; Yunpeng Qin; Mohammad Afsar Uddin; Bomee Jang; Wenchao Zhao; Delong Liu; Han Young Woo; Jianhui Hou
• Keywords: Polythiophene; Acceptor

Here, taking a polythiophene derivative (PBDD4T) as starting polymer, we tried to increase the rotation barrier and hence stabilize its backbone conformation by introducing fluorine into β- β′-position of α-linked bithiophene segments then synthesized new polymer named PBDD4T-2F. Our results demonstrate that between significantly increases after fluorination, so PBDD4T-2F has more stable than PBDD4T. Compared PBDD4T, shows stronger aggregation effect in solution state compact π–π stacking solid thin film also possesses deeper HOMO level. These properties make being an ideal donor material PSCs. When blended with PC71BM, fullerene acceptor, PBDD4T-2F-based device showed power conversion efficiency (PCE) 9.04%, which is 38% higher PBDD4T-based device; when ITIC, non-fullerene PCE 8.69%, almost 20 times device. What more, tandem cell, blend PBDD4T-2F:PC61BM was used for making front subcell, exhibited high 10.12%. The photovoltaic indicate fluorination effective method enhance interchain interaction tune PSCs, especially fullerene-free based on ITIC.