AUTHOR=Zhang Zhenzhen , Yuan Jun , Wei Qingya , Zou Yingping TITLE=Small-Molecule Electron Acceptors for Efficient Non-fullerene Organic Solar Cells JOURNAL=Frontiers in Chemistry VOLUME=6 YEAR=2018 URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2018.00414 DOI=10.3389/fchem.2018.00414 ISSN=2296-2646 ABSTRACT=

The development of organic electron acceptor materials is one of the key factors for realizing high performance organic solar cells. Compared to traditional fullerene acceptor materials, non-fullerene electron acceptors have attracted much attention due to their better optoelectronic tunabilities and lower cost as well as higher stability. Non-fullerene organic solar cells have recently experienced a rapid increase with power conversion efficiency of single-junction devices over 14% and a bit higher than 15% for tandem solar cells. In this review, two types of promising small-molecule electron acceptors are discussed: perylene diimide based acceptors and acceptor(A)-donor(D)-acceptor(A) fused-ring electron acceptors, focusing on the effects of structural modification on absorption, energy levels, aggregation and performances. We strongly believe that further development of non-fullerene electron acceptors will hold bright future for organic solar cells.