High Gain‐bandwidth Product MXene‐Si‐MXene vdW Photodetector for High Signal‐to‐Noise Ratio NIR Single‐Pixel Imaging

Abstract Emerging near‐infrared (NIR) single‐pixel imaging (SPI) technology presents a promising alternative to conventional imaging systems, offering cost efficiency and enhanced durability. The high gain bandwidth product (GBP) of the single‐pixel photodetector (PD) is the primary requirement for high resolution and high imaging speed in SPI. Here, a novel MXene‐Si‐MXene van der Waals (vdW) metal‐semiconductor‐metal (MSM) PD, is demonstrated fabricated via a facile solution process. By incorporating a Ti ₃ C ₂ T _x MXene film, the device exhibits a synergistic photogating effect, leading to an exceptional photogain of up to 7.2 × 10 ³ and a GBP of up to 1.45 GHz under 850 nm illumination at a bias voltage of 2 V, outperforming most currently reported silicon‐based detectors and even many commercial avalanche photodiodes (APDs). Significantly, the high‐quality 512 × 512‐pixel image is successfully achieved at an even 1% sampling rate without any additional filter circuitry by using the PD. The signal‐to‐noise ratio (SNR) of 72.3 dB is the highest value reported to date for SPIs and prior to some NIR array detectors. Thereafter, a high‐quality reconstruction image is also obtained with a SNR of 32.1 dB in visible opaque light. This work paves the way for easy fabrication of high GBP PD for high‐quality NIR SPI.