Controlling defects in continuous 2D GaS films for high-performance wavelength-tunable UV-discriminating photodetectors

A chemical vapor deposition method is developed for thickness‐controlled (one to four layers), uniform, and continuous films of both defective gallium(II) sulfide (GaS): GaS0.87 and stoichiometric GaS. The unique degradation mechanism of GaS0.87 with X‐ray photoelectron spectroscopy and annular dark...

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Huvudupphovsmän: Lu, Y, Chen, J, Chen, T, Shu, Y, Chang, R-J, Sheng, Y, Shautsova, V, Mkhize, N, Holdway, P, Bhaskaran, H, Warner, JH
Materialtyp: Journal article
Språk:English
Publicerad: Wiley 2020
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author Lu, Y
Chen, J
Chen, T
Shu, Y
Chang, R-J
Sheng, Y
Shautsova, V
Mkhize, N
Holdway, P
Bhaskaran, H
Warner, JH
author_facet Lu, Y
Chen, J
Chen, T
Shu, Y
Chang, R-J
Sheng, Y
Shautsova, V
Mkhize, N
Holdway, P
Bhaskaran, H
Warner, JH
author_sort Lu, Y
collection OXFORD
description A chemical vapor deposition method is developed for thickness‐controlled (one to four layers), uniform, and continuous films of both defective gallium(II) sulfide (GaS): GaS0.87 and stoichiometric GaS. The unique degradation mechanism of GaS0.87 with X‐ray photoelectron spectroscopy and annular dark‐field scanning transmission electron microscopy is studied, and it is found that the poor stability and weak optical signal from GaS are strongly related to photo‐induced oxidation at defects. An enhanced stability of the stoichiometric GaS is demonstrated under laser and strong UV light, and by controlling defects in GaS, the photoresponse range can be changed from vis‐to‐UV to UV‐discriminating. The stoichiometric GaS is suitable for large‐scale, UV‐sensitive, high‐performance photodetector arrays for information encoding under large vis‐light noise, with short response time (<66 ms), excellent UV photoresponsivity (4.7 A W–1 for trilayer GaS), and 26‐times increase of signal‐to‐noise ratio compared with small‐bandgap 2D semiconductors. By comprehensive characterizations from atomic‐scale structures to large‐scale device performances in 2D semiconductors, the study provides insights into the role of defects, the importance of neglected material‐quality control, and how to enhance device performance, and both layer‐controlled defective GaS0.87 and stoichiometric GaS prove to be promising platforms for study of novel phenomena and new applications.
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spelling oxford-uuid:f2f85317-f0c0-44ec-be54-20ec59a8ef952022-03-27T12:08:22ZControlling defects in continuous 2D GaS films for high-performance wavelength-tunable UV-discriminating photodetectorsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:f2f85317-f0c0-44ec-be54-20ec59a8ef95EnglishSymplectic ElementsWiley2020Lu, YChen, JChen, TShu, YChang, R-JSheng, YShautsova, VMkhize, NHoldway, PBhaskaran, HWarner, JHA chemical vapor deposition method is developed for thickness‐controlled (one to four layers), uniform, and continuous films of both defective gallium(II) sulfide (GaS): GaS0.87 and stoichiometric GaS. The unique degradation mechanism of GaS0.87 with X‐ray photoelectron spectroscopy and annular dark‐field scanning transmission electron microscopy is studied, and it is found that the poor stability and weak optical signal from GaS are strongly related to photo‐induced oxidation at defects. An enhanced stability of the stoichiometric GaS is demonstrated under laser and strong UV light, and by controlling defects in GaS, the photoresponse range can be changed from vis‐to‐UV to UV‐discriminating. The stoichiometric GaS is suitable for large‐scale, UV‐sensitive, high‐performance photodetector arrays for information encoding under large vis‐light noise, with short response time (<66 ms), excellent UV photoresponsivity (4.7 A W–1 for trilayer GaS), and 26‐times increase of signal‐to‐noise ratio compared with small‐bandgap 2D semiconductors. By comprehensive characterizations from atomic‐scale structures to large‐scale device performances in 2D semiconductors, the study provides insights into the role of defects, the importance of neglected material‐quality control, and how to enhance device performance, and both layer‐controlled defective GaS0.87 and stoichiometric GaS prove to be promising platforms for study of novel phenomena and new applications.
spellingShingle Lu, Y
Chen, J
Chen, T
Shu, Y
Chang, R-J
Sheng, Y
Shautsova, V
Mkhize, N
Holdway, P
Bhaskaran, H
Warner, JH
Controlling defects in continuous 2D GaS films for high-performance wavelength-tunable UV-discriminating photodetectors
title Controlling defects in continuous 2D GaS films for high-performance wavelength-tunable UV-discriminating photodetectors
title_full Controlling defects in continuous 2D GaS films for high-performance wavelength-tunable UV-discriminating photodetectors
title_fullStr Controlling defects in continuous 2D GaS films for high-performance wavelength-tunable UV-discriminating photodetectors
title_full_unstemmed Controlling defects in continuous 2D GaS films for high-performance wavelength-tunable UV-discriminating photodetectors
title_short Controlling defects in continuous 2D GaS films for high-performance wavelength-tunable UV-discriminating photodetectors
title_sort controlling defects in continuous 2d gas films for high performance wavelength tunable uv discriminating photodetectors
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