Morphological Effects on the Performance of Broadband Organic Photomultiplication Photodetectors Containing Selenium Substituted Non‐Fullerene Acceptors

Organic photodetectors (OPDs) with spectral response extending from ultraviolet to near‐infrared domains are of great interest for many applications. Morphological impact on the performance of photomultiplication (PM)‐type OPDs, however, is still rarely investigated so far. Herein, a non‐fullerene a...

Full description

Saved in:
Bibliographic Details
Published in:Advanced functional materials 2023-08, Vol.33 (32), p.n/a
Main Authors: Suthar, Gajendra, Hsiao, Yu‐Tang, Tsai, Kuen‐Wei, Liao, Chuang‐Yi, Chu, Chih‐Wei, Chang, Yi‐Ming, Chen, Fang‐Chung
Format: Article
Language:English
Subjects:
Broadband
Fullerenes
Materials science
Morphology
near infrared
non‐fullerene
Performance enhancement
Phase separation
photodetectors
Photometers
photomultiplication
Selenium
Spectral sensitivity
Substitutes
Trapping
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Organic photodetectors (OPDs) with spectral response extending from ultraviolet to near‐infrared domains are of great interest for many applications. Morphological impact on the performance of photomultiplication (PM)‐type OPDs, however, is still rarely investigated so far. Herein, a non‐fullerene acceptor, Y6‐Se‐HD, is synthesized, in which heavier selenium atoms substitute the sulfur atoms in the core of Y6, and used for fabricating PM‐OPDs. The resulting devices exhibit remarkable PM effects in a very broadband spectral range covering from 320 to 1090 nm. A maximum EQE value of ≈6500% at 860 nm is achieved at a low bias of −1.0 V. As compared with the device prepared with Y6 molecules, the Y6‐Se‐HD OPDs exhibited much enhanced performance. From the morphological analysis, we infer that Y6‐Se‐HD almost covers the entire active layer and avoids the direct contact of the hole‐trapping donor polymers with the Ag electrode, thereby resulting in stronger charge trapping and preventing possible charge recombination and/or quenching. Furthermore, finer phase separation between the donor and acceptor molecules also facilitates hole trapping and strengthens the PM effects. This research highlights the importance of morphological effects on the PM‐OPDs and demonstrates one approach for controlling the device morphology. A selenium‐containing non‐fullerene acceptor is synthesized and used for constructing photomultiplication organic photodetectors. Remarkable photomultiplication effects with a broadband spectral range is observed and the effect of atomic substitution on the morphology is studied. The optimized molecular arrangement ensures strong charge trapping and finer phase separation between the donor and acceptor molecules facilitates hole trapping, thereby strengthening the photomultiplication effects.
ISSN:1616-301X
1616-3028
DOI:10.1002/adfm.202301538