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Photomultiplication type near‐infrared organic photodetectors with a mixed active layer
Author(s) -
Wu Lishuang,
Xu Rudan,
Yao Guangping,
Su Dasheng,
Su Zisheng,
Yang Huishan
Publication year - 2021
Publication title -
microwave and optical technology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 76
eISSN - 1098-2760
pISSN - 0895-2477
DOI - 10.1002/mop.32647
Subject(s) - active layer , optoelectronics , photocurrent , heterojunction , materials science , photodetector , quantum efficiency , acceptor , planar , infrared , layer (electronics) , optics , nanotechnology , physics , computer science , condensed matter physics , thin film transistor , computer graphics (images)
Abstract Photomultiplication type near‐infrared (NIR) organic photodetectors (OPDs) are constructed with lead phthalocyanine (PbPc) and C 60 acted as the donor and acceptor, respectively. Compared with the PbPc/C 60 planar heterojunction device, the PbPc:C 60 mixed active layer devices show enhanced NIR responses. The optimized mixed active layer device displays an external quantum efficiency (EQE) of 22.8% at 870 nm under zero bias, which is about 45% higher than that of planar heterojunction device. Moreover, it also presents a detectivity in the order of 10 12 Jones and an EQE of 400% under applied bias of −8 V, indicating a photocurrent gain obtained in the device. Although the mixed active layer devices have a lower absorption in the NIR region, the donor: acceptor mixed structure increases the donor/acceptor contact area and forms continuous carrier transport paths, which increases the excitons dissociation efficiency and the photogenerated carriers collection efficiency and hence the response of the devices.