Tunable defect-engineered nanohybrid heterostructures: exfoliated 2D WSe2–MoS2 nanohybrid sheet covered on 1D ZnO nanostructures for self-powered UV photodetectors

Abstract

Future innovation of optoelectronic industrial applications for energy saving devices such as self-powered sensors and photodetectors have gained much research attention. Here, for the first time, two-dimensional (2D) WSe₂@MoS₂ nanohybrid sheet heterostructures covering one-dimensional (1D) ZnO nanorod (ZNR) based self-powered ultraviolet (UV) photodetectors are fabricated using a combination of the liquid exfoliation process and a hydrothermal technique. The WSe₂@MoS₂–ZNR device shows a high on/off current ratio (up to 17.2 × 10³), and a fast response time (0.05/0.1 s) at 365 nm illumination under self-bias. In addition, an enhanced UV responsivity (1.6 A W⁻¹) and outstanding photosensitivity (1.16 × 10⁶%) were also observed. The excellent photoresponse, photosensitivity and responsivity were achieved due to strong interactions of the optical materials, enhanced light absorption and efficient charge separation of the present nanohybrid structure. This work provides reliable methodology for the fabrication of a unique 2D nanohybrid covered 1D nanostructure for use in self-powered optoelectronic devices and, useful for energy conservation.