Small Molecule Based Non-Fullerene Acceptors: A Comparative Study.

Organic solar cells (OSCs) have gained attention of the scientific community from the last decade and are now considered as one of the most important source for low-cost power production. The recent rapid progress in non-fullerene acceptors in BHJ indicates that they have potential to compete with fullerene-based BHJ OSCs. The present review addressed the systematic comparison among various acceptors (diketopyrrolopyrrole (DPP), benzothiadiazole (BTD) and perylenediimide (PDI) based acceptors) in order to design and improve the performance of small molecules based non-fullerene acceptors. This review focuses on the performance of small molecule non-fullerene acceptors based on DPP, BTD and PDI for OSCs with respect to the change in molecular structures, energy levels, and PCE. A systematic comparison on the effect of molecular architecture, side chains on their performance is provided with the intention of evaluating the challenge to make highly efficient acceptors for the next generation organic photovoltaics.