Recent advances in small molecular design for high performance non-fullerene organic solar cells

Abstract

Organic solar cells (OSCs) have become one of the most rapidly developing research fields in the past two decades due to their low cost, light weight, and suitability for large-area preparation. OSCs have been using fullerenes and their derivatives as acceptors in the past years, but the shortcomings of fullerenes and their derivatives limit the further improvement of photovoltaic performance. Non-fullerene acceptor materials have been developed due to their modifiable molecular structure, adjustable energy level and regulated blend film morphology, which has set off a research upsurge in the field of OSCs. In this perspective, we mainly summarized the recent advances in innovation of small molecule non-fullerene electron acceptors (SM-NFAs) and structure–property relationships and compatibility of donors and acceptors, as well as the guidelines for future structure designs, morphology control and the direction for the development of SM-NFAs.