Aromatic Heterocycle 1,3,4-Oxadiazole-Substituted Thieno[3,4-b]thiophene to Build Low-Bandgap Polymer for Photovoltaic Application.
Electron-deficient heterocycle 1,3,4-oxadiazole is first introduced to the 2-position of thieno[3,4-b]thiophene (TT) to construct a new building block 2-(thieno[3,4-b]thiophen-2-yl)-5-(alkylthio)-1,3,4-oxadiazole (TTSO) with alkylthio chain. The polymer PBDT-TTSO based on TTSO and benzodithiophene (BDT) exhibits a deep lying highest occupied molecular orbital (HOMO) energy level of -5.32 eV and low-bandgap of 1.62 eV. The power conversion efficiency (PCE) of 5.86% is obtained with a relatively high V OC of 0.74 V, a J SC of 13.1 mA cm(-2), and FF of 60.5%. Furthermore, as S atom in thioether can be oxidized easily, the optoelectronic properties of PBDT-TTSO treated with different oxidants are preliminary investigated. Interestingly, the oxidation products still maintain high PCE with reduction less than 30%. This work demonstrates a new method to regulate HOMO energy levels by introducing electron-deficient aromatic heterocyclic moiety.
CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
Dangqiang
D
Zhu
CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China.
Liang
L
Sun
CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China.
Qian
Q
Liu
CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China.
Shuguang
S
Wen
CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China.
Liangliang
L
Han
CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China.
Xichang
X
Bao
CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China.
Renqiang
R
Yang
D012993:Solar Energy; D013876:Thiophenes / Q000138:chemical synthesis* / Q000737:chemistry*
D013876:Thiophenes
4-b]thiophene; HOMO; energy levels; polymer solar cells; 1,3,4-oxadiazole; thieno[3