The effect of addition of WS2nanosheets on the performance of ZnO nanorods-based photodetector

Abstract

Fabrication of the heterostructure of ZnO/transition metal dichalcogenides (TMD) has attracted much attention to improve the performance of ZnO-based photodetectors. In this work, we report the effect of the addition of WS2 nanosheets on the performance of ZnO nanorods based photodetectors. ZnO nanorods were prepared using the hydrothermal method, and the few layers of WS2 nanosheets were prepared by liquid-phase exfoliation. Exfoliated WS2 solution was deposited on the surface of ZnO nanorods by spin-coating method, and the photodetector performance was calculated via current-voltage measurement in the dark and under laser light sources with a wavelength of UV 365, cyan 505, and red 625 nm. The results show that the dark current significantly decreased after the addition of WS2 on the ZnO nanorods surface. The UV detector performances sensitivity is increased from 129% to 334%, responsivity is increased from 0.93 A/W to 1.11 A/W, and the detectivity is increased from 2.5 × 109 to 4.4 × 109 Jones. However, both samples cannot be used as visible light detectors because of the low photogenerated current.