Ultra‐High Detectivity MBene/Si vdW Schottky Photodiode for Color Single‐Pixel Imaging

Abstract The color single‐pixel imaging (SPI) has received significant attention due to its ability to provide more comprehensive real‐world information compared to grayscale imaging. The performance of single‐pixel photodetector is the primary determinant for the quality of color SPI. Silicon‐based Schottky photodiodes provide desirable qualities for the essential requirements of high detectivity in high resolution color SPI. Herein, a novel Mo 4/3 B 2‐X T Z /Si hexagonal micro‐hole array (SiHMA) van der Waals (vdW) Schottky photodiode is first constructed for application in color SPI. The resultant Schottky junction possesses a Schottky barrier height up to 1.18 eV, thus leading to a dark current density of 1.47 × 10 −13 A cm −2 and an ultra‐high detectivity of 4.4 × 10 14 Jones at zero bias voltage, which are superior to most of Si‐based Schottky photodiodes reported and even some commercial Si photodiodes thus far. Importantly, the high detectivity and low dark current density of the photodiode allow for the use as a photodetector in high resolution Hadamard SPI. Notably, a high‐quality 256 × 256‐pixel color image can be successfully achieved under even 25% sampling rate without an additional filter circuit. This work opens an avenue toward the fabrication of high detectivity Schottky photodiode for high quality color SPI.