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%  

作　　者：Linglong Ye Xueshan Li Yunhao Cai Hwa Sook Ryu Guangkai Lu Donghui Wei Xiaobo Sun Han Young Woo Songting Tan Yanming Sun 

机构地区：[1]School of Chemistry,Beihang University,Beijing 100191,China [2]Department of Chemistry,College of Science,Korea University,Anam-ro 145,Seongbuk-gu,Seoul 136-713,Republic of Korea [3]The College of Chemistry and Molecular Engineering,Zhengzhou University,Zhengzhou 450001,China [4]Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education,College of Chemistry,Xiangtan University,Xiangtan 411105,China

出　　处：《Science China Chemistry》2020年第4期483-489,共7页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China (21674007, 51825301, 21975012, 21875204, 21875204, 21734001);the financial support from the National Research Foundation (NRF) of Korea (NRF-2019R1A2C2085290, 2019R1A6A1A11044070).

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-2Cl. PBF1-C-2Cl, which is composed of BDF and benzo[1,2-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, PBF1-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.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-2Cl. PBF1-C-2Cl, which is composed of BDF and benzo[1,2-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, PBF1-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.

关 键 词：organic solar cells benzo[1 2-b 5-b′]difuran benzo[1 2-c 5-c′]dithiophene-4 8-dione chlorinated THIOPHENE π-bridge 

分 类 号：TQ317[化学工程—高聚物工业] TM914.4[电气工程—电力电子与电力传动]