Light-trapping enhanced ZnO–MoS2 core–shell nanopillar arrays for broadband ultraviolet-visible-near infrared photodetection

Abstract

Two-dimensional (2D) MoS₂ has important applications in the fields of photodetection, photovoltaics, and light-emitting diodes (LEDs) due to its superior electronic and optoelectronic properties. However, the planar thin-layered MoS₂ usually suffers from low light-absorbing ability because of the short transmission path of incident light, which limits the photoelectric conversion quantum efficiency of the thin-layered MoS₂-based photodetectors. Herein, we demonstrate a high-performance ZnO–MoS₂ core–shell nanopillar (NP) array-based photodetector by depositing thin-layered MoS₂ on ZnO NP arrays via magnetron sputtering. With the aid of the ZnO NP arrays, which show a strong light trapping effect, the light-absorbing ability of thin-layered MoS₂ is greatly enhanced. As a result, the ZnO–MoS₂ core–shell NP array-based photodetector exhibits a broadband response spanning from the ultraviolet (UV) to the visible and to the near-infrared (NIR) light region. Compared with the ZnO–MoS₂ planar heterojunction, the photocurrent of the NP array-based photodetector under illumination is improved by up to 60 times. Our work opens up new opportunities for the development of high-performance, broadband photodetectors based on 2D semiconductor materials.