Using BODIPY Unit to Design Molecular Acceptors with Absorption Wavelength of >1000 nm for Organic Photodetectors  

作　　者：Yinghui Wang Jiahui Wang Junhui Miao Jun Liu Lixiang Wang 

机构地区：[1]State Key Laboratory of Polymer Physics and Chemistry,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun 130022,Jilin [2]University of Science and Technology of China,Hefei 230026,Anhui

出　　处：《CCS Chemistry》2024年第11期2794-2803,共10页中国化学会会刊（英文）

基　　金：the financial support from the National Natural Science Foundation of China(grant no.22135007);the Natural Science Foundation of Jilin Province,China(grant no.20230101122JC).

摘　　要：Near-infrared(NIR)organic photodetectors(OPDs)are promising in flexible electronic and imaging sensor applications.However,high-performance NIR-II OPDs with photoresponse wavelength beyond 1000 nm are rare due to the lack of narrow bandgap molecular acceptors.In this work,an A-D-A′-D-Atype molecular acceptor with an onset absorption wavelength of 1150 nm was developed.Its narrow bandgap was benefited by the balanced resonance of the boron-nitrogen covalent bond(B–N)and boron-nitrogen coordination bond(B←N)in thienyl-fused 4-difluoro-4-bora-3a,4a-diaza-s-indacene(BODIPY)unit,as well as the strong intramolecular charge transfer(ICT)effect.The molecule showed a strong NIR absorption with an absorption peak at 1019 nm and an optical bandgap as low as 1.07 eV.Using the molecule as an electron acceptor in OPD device fabrication,a wide photoresponse wavelength range of 300 to∼1150 nm was achieved.At bias of−0.1 V,the device showed a low dark current density of 4.59×10^(−8) A cm^(−2) and high responsivity of 0.29 A W^(−1) at 970 nm,achieving a high peak specific detectivity of 2.39×1012 Jones and remaining a high specific detectivity of 1.59×10^(12) Jones at 1064 nm.These results demonstrate a feasible design of ultra-narrow bandgap molecular acceptors based on BODIPY unit induction of highly sensitive NIR-II OPDs.

关 键 词：organic photodetectors near-infrared II photoresponse molecular acceptors narrow bandgap balanced resonant N–B←N unit 

分 类 号：TN215[电子电信—物理电子学]