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Yang et al. Microstructures 2023;3:2023005 Microstructures
DOI: 10.20517/microstructures.2022.24

Research Article Open Access

An ultraviolet-visible distinguishable broadband

photodetector based on the positive and negative
photoconductance effects of a graphene/ZnO

quantum dot heterostructure

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Xun Yang , Chao-Jun Wang , Shaobo Cheng, Xi-Gui Yang, Jin-Hao Zang, Chong-Xin Shan
Henan Key Laboratory of Diamond Optoelectronic Materials and Devices, Key Laboratory of Material Physics, Ministry of
Education, School of Physics and Microelectronics, Zhengzhou University, Zhengzhou 450052, Henan, China.
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Authors contributed equally.
Correspondence to: Dr. Shaobo Cheng, Henan Key Laboratory of Diamond Optoelectronic Materials and Devices, Key
Laboratory of Material Physics, Ministry of Education, School of Physics and Microelectronics, Zhengzhou University, Zhengzhou
450052, Henan, China. E-mail: chengshaobo@zzu.edu.cn; Dr. Chong-Xin Shan, Henan Key Laboratory of Diamond
Optoelectronic Materials and Devices, Key Laboratory of Material Physics, Ministry of Education, School of Physics and
Microelectronics, Zhengzhou University, Zhengzhou 450052, Henan, China. E-mail: cxshan@zzu.edu.cn

How to cite this article: Yang X, Wang CJ, Cheng S, Yang XG, Zang JH, Shan CX. An ultraviolet-visible distinguishable
broadband photodetector based on the positive and negative photoconductance effects of a graphene/ZnO quantum dot
heterostructure. Microstructures 2023;3:2023005. https://dx.doi.org/10.20517/microstructures.2022.24

Received: 6 Sep 2022 First Decision: 9 Oct 2022 Revised: 21 Oct 2022 Accepted: 25 Nov 2022 Published: 10 Jan 2023

Academic Editor: Zibin Chen Copy Editor: Fangling Lan Production Editor: Fangling Lan

Abstract
Broadband photodetectors covering the ultraviolet (UV) to visible range are significant for applications in
communication and imaging. Broadband photodetectors with the capacity to distinguish wavelength bands are
highly desirable because they can provide additional spectral information. Herein, we report a UV-visible
distinguishable broadband photodetector based on a graphene/ZnO quantum dot heterostructure. The
photodetector exhibits negative photoconductance under visible illumination because the adsorbents on graphene
act as scattering centers to reduce the carrier mobility. In contrast, under UV illumination, the photodetector shows
positive photoconductance as the photogenerated electrons in the ZnO quantum dots transfer to the graphene,
thereby increasing the conductivity. Thus, the detection and distinction of UV and visible illumination can be
realized by utilizing the opposing photoconductivity changes. These results offer inspiration for the design of
multifunctional broadband photodetectors.

© The Author(s) 2023. Open Access This article is licensed under a Creative Commons Attribution 4.0
International License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, sharing,
adaptation, distribution and reproduction in any medium or format, for any purpose, even commercially, as
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