High-Performance 1D CdS/2D Te Heterojunction Photodetector

Abstract Van der Waals heterostructures facilitate the versatile combination of two-dimensional (2D) materials with semiconductors that possess distinctive band structures, offering a promising platform for developing photodetectors with extensive spectral range and high sensitivity. This study showcases the flawless integration of one-dimensional (1D) CdS nanowires with 2D Te nanosheets, resulting in the creation of a high-performance, mixed-dimensional heterojunction photodetector. Bandgap engineering at the CdS/Te interface promotes Type II band alignment, markedly improving the separation and transport of photo-generated charge carriers. Additionally, the interaction between materials of different dimensions significantly enhances the device’s photoresponsivity and detectivity. When operated at low bias, the photodetector displays an impressive rectification ratio of up to 8.57×10 3 , along with superior photoelectric performance spanning the ultraviolet to visible light spectrum. Particularly under 450 nm wavelength laser illumination, the device displayed a high photoresponsivity of up to 126 A W −1 , a high detectivity of 1.03×10 10 Jones, an external quantum efficiency of up to 3.49×10 2 %, and a rapid response time of 35 ms. The photoresponsivity of this device was at least an order of magnitude higher than other reported mixed-dimensional heterojunction photodetectors. The development of the 1D CdS/2D Te heterostructure opens new pathways for high-sensitivity, broad-spectrum photodetection technologies.