Easily synthesized pyrene-based nonfullerene acceptors for efficient organic solar cells

Abstract

Pyrene is a commercial fused-ring unit and has attracted much attention in the field of organic photoelectric functional materials. Herein, two non-fullerene acceptors (NFAs) Py-2H and Py-2F based on pyrene core have been developed. Unlike most others NFAs, Py-2H and Py-2F were synthesized via a simple and easy synthesis method, and this is fundamental for commercialization of organic solar cells (OSCs). Compared with Py-2H, fluorinated Py-2F exhibited narrower optical bandgap of 1.66 eV, better π-π stacking, lower frontier molecular orbital levels, and its PBDB-T:Py-2F blend film exhibited triple electron mobility. As a result, PBDB-T:Py-2F solar cells afforded a decent power conversion efficiency (PCE) of 9.73%, with an open-circuit voltage (VOC) of 0.92 V, a short circuit current (JSC) of 15.44 mA/cm2 and a fill factor (FF) of 68.22%. As comparison, PBDB-T:Py-2H cell just achieved only one-half PCE of 5.13%. These results demonstrated that NFAs based on fused-ring pyrene core are promising for organic photovoltaic applications due to the simple synthesis, low cost, and decent photovoltaic performance.