An Asymmetric Perylene Diimide Dimer Acceptor for High Performance Organic Solar Cells

Abstract

AbstractThe vinylene‐bridged helical perylene diimide (PDI) dimer (PDI2) with a build‐in twisted configuration is an alternative building block to the parent PDI for the construction of efficient non‐fullerene acceptor (NFAs). Moreover, it has been proved asymmetric strategy plays a vital role in the development of NFAs. Herein, we designed and synthesized a pair of acceptor‐donor‐acceptor (A−D‐A) type PDI2 derivatives, namely IDTIC‐PDI and IDT‐diPDI2, which contain asymmetric and symmetric end‐cap units, respectively. To determine the structure–performance relationships of asymmetric strategy, the organic solar cells (OSCs) based on these two molecules were fabricated and measured. The asymmetric IDTIC‐PDI based device exhibits a much higher PCE of 8.23 % than that of symmetric IDT‐diPDI2 (5.21 %). These results reveal that symmetry breaking provides an effective way to optimize the photovoltaic performances of PDI2 based OSCs.