Guest electron-accepting polymer doping enables green solvent-processed all-polymer solar cells with 16.37% efficiency

Abstract

The development of polymerized small molecule acceptors (PSMA) has pushed all-polymer solar cells (all-PSCs) to break through power conversion efficiency (PCE) of 16–17%. However, these PCEs are obtained by halogenated solvents processing, which will cause serious harm to the environment and human health. To make the PSMA-based all-PSCs suitable for non-halogenated solvent processing, we introduced PZT into a typical high-efficiency all-PSCs system based on PBDB-T:PYF-T, to improve the solubility of PYF-T in non-halogenated solvent toluene (TL). PZT and PYF-T worked in an alloy-like model due to excellent miscibility induced by the similar molecular structure. A top PCE of 16.37% was obtained for TL-processed all-PSCs based on PBDB-T:PYF-T:PZT, which represented the highest PCE value for all-PSCs processed by non-halogenated solvents. In addition, the doping of PZT can significantly improve the ambient processing stability, photo-stability and thermal-stability of TL-processed all-PSCs, proving that polymer doping strategy enables all-PSCs compatible for practical applications.