An asymmetric A-D-π-A type non-fullerene acceptor enables high-detectivity near-infrared organic photodiodes

摘要

Narrow bandgap non-fullerene acceptors(NFAs)are relevant as key materials components for the fabrication of near-infrared(NIR)organic solar cells(OSCs)and organic photodiodes(OPDs)thanks to their complementary absorption,tunable energy levels,and enhanced stability.However,high-performance NIR photodetectors are still scarce due to the absence of narrow bandgap NFAs.Herein,an asymmetric A-D-π-A type NFA,named ABTPV-S,with a broad optical absorption approaching 1,000 nm is designed and synthesized through integrating alkylthio side chains and a vinyleneπ-bridge.The optimal inverted OPD device exhibits an excellent performance with a photoresponsivity of 0.39 AW-1,a noise current of 2.25×10^(-14)A Hz^(-0.5),a specific detectivity(D*)of 3.43×10^(12)Jones at 840 nm,and linear dynamic range(LDR)of 140 d B.In addition,the rise and fall times for ABTPV-S-based OPDs also reach 1.07 and 0.71μs,respectively.ABTPV-S-based OPDs exhibit a high D*over 1012Jones at 950 nm,which is a competitive result for the self-powered photodiode-type NIR OPDs.These findings highlight the outstanding potential of asymmetric A-D-π-A type NIR NFAs for high-performance OPDs competing with their silicon counterparts.