Zhang Yong, Associate Professor, from the School of Electronic Information Engineering recently published the title "High performance self-powered CuZnS/GaN UV photodetectors with ultrahigh on/off ratio (3×10⁸)" in the internationally renowned journal " Journal of Materials Chemistry C " (Area of SCI Division, Chinese Academy of Sciences, IF = 7.059) with the first author and Changshu Institute of Technology as the first completion unit. This study reported a heterojunction UV photodetector between p-CuZnS and n-GaN, and studied the self-powered performance of the CuZnS/GaN photodetector. It was found that this CuZnS/GaN device exhibits high photocurrent (19 μA), fast response speed (0.14/40 ms) and ultrahigh on/off ratio (3×10⁸) under 350 nm light illumination at zero bias. These results suggest that the CuZnS/GaN film devices have high potential as high-performance self-powered UV photodetectors for practical applications. Thesis link:

https://pubs.rsc.org/en/content/articlelanding/2021/TC/D1TC00137J#!divAbstract

Paper Title：High performance self-powered CuZnS/GaN UV photodetectors with ultrahigh on/off ratio (3×10⁸)

Journal：Journal of Materials Chemistry C

Abstract：

The heterojunction UV photodetector based on p-CuZnS and n-GaN is prepared by a simple chemical bath deposition. The CuZnS/GaN film device shows a significantly enhanced photocurrent at 3 V and 350 nm, a good rectifying behavior (ratio of 19 000 at ±3 V) and a large open circuit voltage (0.55 V). Furthermore, the CuZnS/GaN photodetector exhibits excellent self-powered characteristics under 350 nm light illumination, including a high photocurrent (19 μA), a fast response speed (0.14/40 ms) and an ultrahigh on/off ratio (3×10⁸). More importantly, the CuZnS/GaN photodetector presents a large detectivity of 8×10¹³ Jones and an ultrahigh linear dynamic range of 137 dB at 320 nm light illumination at zero bias. These results suggest that the CuZnS/GaN film devices have great potential as high-performance self-powered UV photodetectors for practical applications.

Figure 1 (a) Schematic illustration of the CuZnS/GaN device structure. (b) I-V characteristics of the CuZnS/GaN heterojunction device. (c) I-t characteristics, (d) the normalized single pulse response, (e) the detectivity and (f) the linear dynamic range spectra for the CuZnS/GaN PD at zero bias.

Yong Zhang is an associate professor in School of Electronic and Information Engineering, Changshu Institute of Technology. He did post-doctoral research at Fudan University in 2017-2020. He received his PhD degree in 2016 from Beihang University. He research interests focus on the preparation of wide band gap semiconductor and its photodetector. He has published 15+ papers in prestigious international refereed journals.