Jump to main content
Jump to site search


Nonhalogen solvent-processed high efficiency polymer solar cells based on polymer donor containing chlorine and trialkylsilyl substituted thienyl benzodithiophene donor unit

Abstract

Fluorine and alkylsilyl substitutions are two important strategies to reduce the energy levels, increase the absorption coefficient and hole mobility of photovoltaic materials simultaneously. Similar to fluorination, chlorination can also induce the intermolecular non-covalent interactions of Cl-H/S/Cl. Moreover, due to chlorine (Cl) atom contains empty 3d orbitals that can hold π-electrons from the conjugated skeleton, chlorination can decrease molecular HOMO level more effectively than fluorination. Herein, we developed two wide bandgap polymer donors PBZ-Cl and PBZ-ClSi based on Cl atom, and combined Cl atom and alkylsilyl substituted thienyl benzodithiophene (BDTT-Cl and BDTT-ClSi) as donor units, respectively. From the control polymer PBZ to PBZ-Cl and then to PBZ-ClSi, the polymers show gradually reduced HOMO level, increased absorption coefficient and improved charge mobility. As a result, the PBZ-ClSi:IT-4F-based PSCs fabricated by the nonhalogen solvents gained a high power conversion efficiency (PCE) of 12.8% with high open-circuit voltage (Voc) of 0.93 V, short-circuit current density (Jsc) of 19.2 mA cm-2, fill factor (FF) of 71.5% and a low energy loss of 0.57 eV, while the PSCs based on PBZ and PBZ-Cl only obtain lower PCEs of 6.4% and 9.7%, respectively. The PCE of 12.8% is one of the highest values recorded for the nonhalogen solvents-processed PSCs to date. The results indicate that the combination of Cl atom and alkylsilyl substitutions is a simple and effective method for designing high efficiency polymer photovoltaic materials.

Back to tab navigation

Supplementary files

Publication details

The article was received on 06 Nov 2018, accepted on 30 Nov 2018 and first published on 01 Dec 2018


Article type: Paper
DOI: 10.1039/C8TA10662B
Citation: J. Mater. Chem. A, 2018, Accepted Manuscript
  •   Request permissions

    Nonhalogen solvent-processed high efficiency polymer solar cells based on polymer donor containing chlorine and trialkylsilyl substituted thienyl benzodithiophene donor unit

    W. Su, G. L. Li, Q. Fan, Q. Zhu, X. Guo, J. Chen, J. Wu, W. Ma, M. Zhang and Y. Li, J. Mater. Chem. A, 2018, Accepted Manuscript , DOI: 10.1039/C8TA10662B

Search articles by author

Spotlight

Advertisements