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Filter‐Free Band‐Selective Organic Photodetectors
Author(s) -
Lan Zhaojue,
Lau Ying Suet,
Wang Yiwen,
Xiao Zuo,
Ding Liming,
Luo Dan,
Zhu Furong
Publication year - 2020
Publication title -
advanced optical materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.89
H-Index - 91
ISSN - 2195-1071
DOI - 10.1002/adom.202001388
Subject(s) - photodetection , materials science , photodetector , responsivity , optoelectronics , cutoff frequency , optics , wavelength , optical filter , absorption (acoustics) , active layer , layer (electronics) , ray , filter (signal processing) , heterojunction , visible spectrum , nanotechnology , physics , computer science , composite material , computer vision , thin film transistor
The present band‐selective photodetection is realized by incorporating different optical filters with broadband photodetectors (PDs). However, the use of the optical filters reduces the overall PD sensitivity. This work reports on the effort to develop high‐performance filter‐free band‐selective organic photodetectors (OPDs) having a heterostructure photoactive layer architecture, comprising a semiconducting shorter‐wavelength light depletion layer and a bulk heterojunction (BHJ) layer with an extended absorption to longer wavelengths. The filter‐free band‐selective photodetection is realized by adjusting the difference in wavelengths between the transmission cut‐off wavelength of the semiconducting light depletion layer and the absorption edge of the BHJ layer. For example, a filter‐free visible‐blind near‐infrared OPD, with a spectral rejection ratio of 100, a high responsivity of 0.39 A W −1 , a high −3 dB cutoff frequency of 80 kHz, and a fast response time of ≈7 µs, is demonstrated, offering an exciting option for a plethora of applications in imaging and light communications.