Investigation of isomerization effects on the photovoltaic performance of fused-ring electron acceptors via side-chain position manipulation

Abstract

Three FREA isomers, IUIC-in, IUIC-mid and IUIC-out, were developed to investigate the effects of side-chain position on molecular properties and photovoltaic performance. Among them, IUIC-mid based devices exhibit the lowest trap density and finest phase separation, contributing to the highest mobilities, weakest charge recombination and most efficient exciton dissociation. Therefore, the IUIC-mid based OSC gains the highest PCE of 13.1%.