Synthesis and characterization of new nonfullerene electron acceptors with a chrysene core

Abstract

The utilization of non-fullerene acceptors has greatly promoted the development of organic photovoltaics in past few years. Herein, two new non-fullerene small-molecule electron acceptors, CRIC and CRIC-4F, with a four-fused-rings containing chrysene core, are designed and synthesized. Benefiting from the rigid and planar chrysene segment, these two acceptors exhibit strong intramolecular π electron transition with intense optical absorption from 550 to 750 nm. Both molecules present deep lowest unoccupied molecular orbital (LUMO) energy levels at around −4.0 eV, thereby making them suitable to employ as electron acceptors. In combination with electron donor J52-2F, organic solar cells based on CRIC achieved a decent power conversion efficiency (PCE) of 6.12% with a low energy loss of 0.59 eV owning to their complementary absorption, higher energy levels, and reduced charge recombination, thus surpassing the J52-2F:CRIC-4F based counterpart (PCE = 5.61%). This work demonstrates that chrysene derivatives are potential acceptors for applications in organic photovoltaics with low energy losses.