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  • High‐Detectivity UV–Visible–NIR Broadband Polymer Photodetector with Polymer Charge Blocking Layer Cross‐Linked by Organic Photocrosslinker
Title: High‐Detectivity UV–Visible–NIR Broadband Polymer Photodetector with Polymer Charge Blocking Layer Cross‐Linked by Organic Photocrosslinker
Abstract Ultraviolet (UV), visible, and near‐infrared (NIR) broadband organic photodetectors are fabricated by sequential solution‐based thin film coatings of a polymer electron blocking layer (EBL) and a polymer photoactive layer. To avoid damage to a preceding polymer EBL during a subsequent solution‐based film coating of a polymer photoactive layer due to lack of solvent orthogonality, 2‐(((4‐azido‐2,3,5,6‐tetrafluorobenzoyl)oxy)methyl)−2‐ethylpropane‐1,3‐diyl bis(4‐azido‐2,3,5,6‐tetrafluorobenzoate) (FPA‐3F) is used as a novel organic cross‐linking agent activated by UV irradiation with a wavelength of 254 nm. Solution‐processed poly[N,N′‐bis(4‐butylphenyl)‐N,N′‐bis(phenyl)‐benzidine] (poly‐TPD) films, which are cross‐linked with a FPA‐3F photocrosslinker, are used for a preceding polymer EBL. A ternary blend film composed of PTB7‐Th, COi8DFIC, and PC71BM is used as a NIR‐sensitive organic photoactive layer with strong photosensitivity in multispectral (UV–visible–NIR) wavelengths of 300–1,050 nm. Poly‐TPD films are successfully cross‐linked even with a very small amount of 1 wt% FPA‐3F. Small amounts of FPA‐3F have little detrimental effect on the electrical and optoelectronic properties of the cross‐linked poly‐TPD EBL. Finally, organic NIR photodetectors with a poly‐TPD EBL cross‐linked by the small addition of FPA‐3F (1 wt%) show the detectivity values higher than 1 × 1012Jones for the entire UV–visible–NIR wavelengths from 300 nm to 1050 nm, and the maximum detectivity values of 1.41 × 1013Jones and 8.90 × 1012Jones at the NIR wavelengths of 900 and 1000 nm, respectively.  more » « less
Award ID(s):
2314294
PAR ID:
10537435
Author(s) / Creator(s):
; ; ; ; ; ; ; ;
Publisher / Repository:
Wiley
Date Published:
Journal Name:
Advanced Functional Materials
ISSN:
1616-301X
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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