Organic solar cells based on chlorine functionalized benzo[1,2-b:4,5-b']difuran-benzo[1,2-c:4,5-c']dithiophene-4,8-dione copolymer with efficiency exceeding 13％

• 来源期刊: 中国科学:化学（英文版）
• 年，卷（期）: 2020,（4）
• 页码范围: 483-489
• 页数: 7页
• 语种: 英文

摘要

Benzo[1,2-b:4,5-b']dithiophene (BDT) has been widely used to construct donor-acceptor (D-A) copolymers in organic solar cells (OSCs).However,benzo[1,2-b:4,5-b']difuran (BDF),an analogue of BDT,has received less attention than BDT.The photovoltaic performance of BDF copolymers has lagged behind that of BDT copolymers.Here,we designed and synthesized two BDF copolymers,PBF1-C and PBF1-C-2C1.PBF1-C-2Cl,which is composed of BDF and benzo[l,2-c:4,5-c']dithiophene-4,8-dione connected by a chlorinated thiophene π-bridge,displays a low-lying highest occupied molecular orbital energy level,which helps in yielding a high open-circuit voltage (Voc) in OSCs.As a result,when blended with Y6,PBF 1-C-2Cl-based devices showed a high Voc of 0.83 V and a power conversion efficiency (PCE) of 13.10％.To the best of our knowledge,the PCE of 13.10％ is among the highest efficiency values for OSCs based on BDF copolymers.