Enhanced efficiency of polymer solar cells by improving molecular aggregation and broadening the absorption spectra
Journal article, 2019

Alkylthio-substituted thiophene-based benzo[1,2-b:4,5-b’]dithiophene (BDT) was used to construct PBDTS-DTBT, a medium band gap donor-acceptor (D-A) polymer with 5,6-difluoro-4,7-bis[4-(2-octyldodecyl)thiophene-2-yl]benzo[c] [1,2,5]thiadiazole (DTBT). The incorporation of sulfur atoms into the side chains not only lowered the highest occupied molecular orbital (HOMO) energy level but also improved molecular aggregation and thus afforded lower band gap (1.68 eV) with full width at half maximum (FWHM) of 170 nm in comparison to that of the analogous polymer (PBDT-DTBT) without sulfur atoms in side chains. Therefore, the bulk heterojunction polymer solar cells based on PBDTS-DTBT with 2% diiodooctane (DIO) as processing additive showed a high power conversion efficiency (PCE) of 9.73% with high open-circuit voltage (V OC , 0.93 V), large short-circuit current density (J SC , 14.23 mA/cm 2 ) and high fill factor (FF, 0.735).

Alkylthio-substituents

Polymer solar cells

Molecular aggregation

Absorption spectra

High fill factor

Author

W. Chen

Qingdao University

Donghua University

W. F. Shen

Qingdao University

Huan Wang

Qingdao University

Fushuai Liu

Chinese Academy of Sciences

Linrui Duan

Chinese Academy of Sciences

Xiaofeng Xu

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Polymer Technology

D. Q. Zhu

Chinese Academy of Sciences

Meng Qiu

Chinese Academy of Sciences

Ergang Wang

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Ergang Wang Group

R. Yang

Chinese Academy of Sciences

Dyes and Pigments

0143-7208 (ISSN)

Vol. 166 42-48

Subject Categories

Physical Chemistry

Theoretical Chemistry

Condensed Matter Physics

DOI

10.1016/j.dyepig.2019.03.014

More information

Latest update

4/8/2019 1