Ultralow dark-current self-powered VS2/SiO2/Si MIS photodiode for highly sensitive broadband detection

Widely used silicon (Si)-based optoelectronic components based on PN or Schottky junctions face issues such as high noise levels and poor weak-light detection capabilities. Herein, we present a high-performance 1T-VS2/SiO2/Si metal–insulator–semiconductor photodiode. By inserting an ultrathin insulating layer to increase the barrier height and suppress carrier tunneling, the photodiode achieves an ultralow dark current of 2 × 10−13 A and a sensitive self-powered photoresponse across the ultraviolet to short-wavelength near-infrared spectrum. Significantly, it exhibits a maximal ratio of photocurrent to dark current (Ilight/Idark) up to 107 and can detect weak light signals down to 80 nW/cm2. Our study offers a strategy to suppress dark current and enhance sensitivity in zero-energy optoelectronic devices, showing great potential for weak-light sensing and broadband photodetection applications beyond Si-detection limits.