Ultra-low dark current photodetector based on two-dimensional CuCrP₂S₆ material

Metal thiophosphates have recently emerged as promising two-dimensional (2D) materials for the next-generation photodetectors due to their unique physical and optoelectronic properties. Among them, CuCrP₂S₆ (CCPS) has shown strong potential for photodetection applications. In this study, we developed a photodetector based on CCPS nanoflakes. The optimized device, featuring a 3 μm channel length and a 60 nm CCPS layer, exhibited impressive optoelectronic performance, with a responsivity of 7 mA/W and a detectivity of 6 × 10⁸ Jones for 450 nm light with the light intensity of 0.02 mW/mm². The device achieved an exceptionally low dark current of ∼300 fA, surpassing other reported 2D layer-based photodetectors. The long-term stability of the photodetector was demonstrated through 1500 cyclic light pulses. Furthermore, a 3 × 3 array device was constructed, showcasing outstanding optical imaging capabilities and operational stability. These findings provide crucial experimental evidence supporting the future fabrication of large-scale, high performance, low power, and highly stable photodetector arrays.