Defect-controlled photoresponse in GaOOH/reduced graphene oxide composites for ultraviolet-C photodetectors

Abstract

GaOOH/reduced graphene oxide (rGO) composites are investigated for UVC photodetection with a defect-controlled photoresponse. The morphology and crystallinity of GaOOH grown on rGO are strongly influenced by the Ga(NO3)3 concentration. Excess precursor induces GaOOH aggregation, reducing the effective GaOOH/rGO interfacial area and generating trap states in GaOOH. These traps act as recombination centers that shorten the carrier lifetime and suppress the photocurrent. The optimized 10% Ga(NO3)3 device shows the best performance, achieving a responsivity of 63.82 mA/W and an external quantum efficiency of 31%, about four times higher than the 30% sample and ∼220 times higher than previously reported GaOOH-based photodetectors.

Metadata

Item Type:	Article
Authors/Creators:	Khanh, N. https://orcid.org/0009-0002-0539-235X Do, H.-B. https://orcid.org/0000-0003-3274-5050 Nguyen, T.-H. https://orcid.org/0009-0008-7123-8856 Ngo, T.-H.-L. https://orcid.org/0009-0001-2860-1495 Phan-Gia, A.-V. https://orcid.org/0009-0008-7412-5232 Tran, T.T.V. https://orcid.org/0000-0003-1134-6640 De Souza, M.M. https://orcid.org/0000-0002-7804-7154 Le, H.-M. https://orcid.org/0009-0009-8107-4995 Linh, L. https://orcid.org/0009-0003-7002-7049 Nawaz, M.H. https://orcid.org/0009-0006-6157-4659 Chuang, F.-C. https://orcid.org/0000-0003-0351-4253 Pham, P.V. https://orcid.org/0000-0001-7951-1329 Nguyen Dang, N. https://orcid.org/0000-0003-4434-0763
Copyright, Publisher and Additional Information:	© 2026 The Authors. Except as otherwise noted, this author-accepted version of a journal article published in ACS Applied Electronic Materials is made available via the University of Sheffield Research Publications and Copyright Policy under the terms of the Creative Commons Attribution 4.0 International License (CC-BY 4.0), which permits unrestricted use, distribution and reproduction in any medium, provided the original work is properly cited. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/
Keywords:	gallium oxyhydroxide; GaOOH/rGO composite; UVC photodetection; defect-controlled photoresponse; fast and slow charges
Dates:	Submitted: 17 March 2026 Accepted: 17 April 2026 Published (online): 22 April 2026 Published: 12 May 2026
Institution:	The University of Sheffield
Academic Units:	The University of Sheffield > Faculty of Engineering (Sheffield) > School of Electrical and Electronic Engineering
Date Deposited:	30 Apr 2026 14:22
Last Modified:	15 May 2026 14:41
Status:	Published
Publisher:	American Chemical Society (ACS)
Refereed:	Yes
Identification Number:	10.1021/acsaelm.6c00519
Open Archives Initiative ID (OAI ID):	oai:eprints.whiterose.ac.uk:240655

CORE (COnnecting REpositories)

Defect-controlled photoresponse in GaOOH/reduced graphene oxide composites for ultraviolet-C photodetectors

Abstract

Metadata

Download

Accepted Version

Export

Statistics