摘要
Comprehensive Summary In this work,we adopt a“heteroatom side-chains”modification strategy to modify the thiophene units in A-DA'D-A(acceptor-donor-acceptor’-donor-acceptor)type pentacyclic SMAs(small molecule acceptors),that is,introducing branched alkyl chain at theβ-position of thiophene instead of straight alkyl chain,and then introducing oxygen atom at the third-position on the basis of branched chain.Two new pentacyclic SMAs(BZ4F-EH and BZ4F-OEH)were synthesized,and the influence of the heteroatom side-chains on photoelectric properties of A-DA'D-A type pentacyclic SMAs was systematically studied.Compared with our previously reported BZ4F(Y26),BZ4F-EH shows slightly blue-shifted absorption,while BZ4F-OEH has obvious red-shifted absorption.As a result,BZ4F-OEH-based binary device achieved a high power conversion efficiency(PCE)of 16.56%with a fill factor(FF)of 79.3%,which is the highest efficiency of pentacyclic SMAs to date.
基金
the National Natural Science Foundation of China(Nos.52125306,22005347,21875286)
the Natural Science Foundation of Hunan Province(2021JJ20068)
the Central South University Innovation-Driven Research Program(No.2023CXQD052).