Low Dark-Current V₂CT_x/n-Si Van Der Waals Schottky Photodiode for Hadamard Single-Pixel Imaging

Herein, we presented a novel low dark-current V2CTx/n-Si van der Waals (vdW) Schottky photodiode. The device exhibited the highest Schottky barrier height of 1.37 eV for Si-based Schottky barrier diodes (SBDs), yielding an ultra-low dark-current density approaching to $1.57\times 10^{-{12}}\text{A}$ /cm2 at zero bias voltage and ~ $1.25\times 10^{-{7}}\text{A}$ /cm2 at reverse bias of −2 V, which are smaller than most of previous Si-based SBDs. The performance of the presented photodiode was tested as a single-pixel detector in a Hadamard Single-pixel Imaging (HSI) system under self-powered operating model. Due to low dark-current together with a large linear dynamic range (~77 dB), a high-quality $128\times128$ -pixel image was achieved under even 25% sampling rate without additional filter processes for our device.