Molecule Design of Novel Electron Acceptor with Superior Chemical Stability for Photovoltaic Applications

Abstract

The stability of organic photovoltaic (OPV) cells is significantly affected by the decomposition of acceptor–donor–acceptor type non-fullerene acceptors (NFAs), bringing a significant challenge for the manufacture and applications. Herein, a novel acceptor with superior chemical stability named GS-22 is designed and synthesized and the relationship between molecular structure and chemical stability is investigated. Based on structure analysis, the exocyclic vinyl groups are proven to exhibit inferior chemical stability and can be easily destructed under an alkaline environment and illumination. Owing to the single-bonded end groups and the completely non-fused core, GS-22 shows remarkably high chemical stability, contributing to obviously improved device stability. Impressively, the fitting T80 (the lifetime when power conversion efficiency retains 80% of the initial value) of the encapsulated OPV cell reaches 3770 h. This work provides an effective molecular design strategy for NFAs with superior chemical stability.