摘要
Charge manipulation is crucial in optoelectronic devices.The unoptimized interfacial charge injection/extraction in solution-processed bulkheterojunction(BHJ)organic photodetectors(OPDs)presents significant challenges in achieving high detectivity and fast response speed.Here,we first develop an approach for intrinsic charge manipulation induced by molecularly engineered donors to block electron injection and facilitate hole extraction between the indium tin oxide(ITO)transparent anode and the photoactive layer.By utilizing a polymer donor with 3,4-ethylenedioxythiophene(EDOT)as the conjugated side chain,a polymer-rich layer forms spontaneously on the ITO substrate due to the increased oxygen interactions between ITO and EDOT.This results in electron-blocking-layer(EBL)-free devices with lower dark current and noise without a reduction in responsivity compared to control devices.As a result,the EBL-free devices exhibit a peak specific detectivity of 2.36×10^(13) Jones at 950 nm and achieve a-3 dB bandwidth of 30 MHz under-1 V.Enhanced stability is also observed compared to the devices with poly(3,4-ethylenedioxythiophene)polystyrene sulfonate(PEDOT:PSS).This work demonstrates a new method to intrinsically manipulate charge injection in BHJ photoactive layers,enabling the fabrication of solution-processed EBL-free OPDs with high sensitivity,rapid response,and good stability.
基金
the Shenzhen Fundamental Research Funding(Key Program,No.JCYJ20200109141405950)
Shenzhen Key Lab Funding(No.ZDSYS2015052915525382)
the National Natural Science Foundation of China(No.51703092)
the European Research Council for support under the European Union's Horizon 2020 Research and Innovation Program(Nos.742708 and 648901)
support under Guangdong Provincial Natural Science Foundation General Project(No.2024A1515012318)
Guangdong Basic and Applied Basic Research Foundation(No.2023A1515111140)
Shenzhen government for support under the special appointed position-“Pengcheng Peacock Plan-C”
The Chinese University of Hong Kong(Shenzhen)for support under The University Development Fund(No.UDF01003117)
Special Funds for High-Level Universities-Talent Projects-“Presidential Young Fellow”(No.UF02003117).
