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High-Performance Ultraviolet Photodetector Based on Graphene Quantum Dots Decorated ZnO Nanorods/GaN Film Isotype Heterojunctions

Authors :
Yuankun Zhu
Ping Wang
Aiying Chen
Ding Wang
Hui-Jun Li
Zhao Shuang
Xianying Wang
Junhe Yang
Deshuai Liu
Jinrao Gao
Source :
Nanoscale Research Letters, Nanoscale Research Letters, Vol 13, Iss 1, Pp 1-9 (2018)
Publication Year :
2018
Publisher :
Springer Science and Business Media LLC, 2018.

Abstract

A novel isotype heterojunction ultraviolet photodetector was fabricated by growing n-ZnO nanorod arrays on n-GaN thin films and then spin-coated with graphene quantum dots (GQDs). Exposed to UV illumination with a wavelength of 365 nm, the time-dependent photoresponse of the hybrid detectors manifests high sensitivity and consistent transients with a rise time of 100 ms and a decay time of 120 ms. Meanwhile, an ultra-high specific detectivity (up to ~ 1012 Jones) and high photoresponsivity (up to 34 mA W−1) are obtained at 10 V bias. Compared to the bare heterojunction detectors, the excellent performance of the GQDs decorated n-ZnO/n-GaN heterostructure is attributed to the efficient immobilization of GQDs on the ZnO nanorod arrays. GQDs were exploited as a light absorber and act like an electron donor to effectively improve the effective carrier concentration in interfacial junction. Moreover, appropriate energy band alignment in GQDs decorated ZnO/GaN hybrids can also be a potential factor in facilitating the UV-induced photocurrent and response speed.

Details

ISSN :
1556276X and 19317573
Volume :
13
Database :
OpenAIRE
Journal :
Nanoscale Research Letters
Accession number :
edsair.doi.dedup.....294a58f1238ee6727f6efcc452776994