Molecular dyads with non-fused electron acceptor backbones for single-component organic solar cells

Abstract

Despite years of development, the efficiencies of single molecular organic solar cells (SMOSCs) are still kept at low levels, mainly because of the lack of high-performance acceptor segments in this field. In this work, we report two molecular dyads, SW1 and SW2, by introducing an unfused non-fullerene acceptor as the acceptor segments and linear oligomers as the donor segments and linking by flexible alkyl chains. Excellent photovoltaic performance of SW1 is achieved, leading to a power conversion efficiency of 3.78%, which is a record high for non-fullerene acceptor-based SMOSCs reported in the literature thus far. Notably, both SW1 and SW2 SMOSCs exhibit promising long-term storage and photo stabilities, indicating great potential in practical application. The success of our strategy provides a new motif for designing highly efficient SMOSCs. It can be expected that the single-component materials especially in terms of molecular dyads have stepped into a new developing era.