2D CuInP2Se6 in High‐Sensitivity UV‐vis And X‐Ray Detection.

Metal thio(seleno)phosphates are renowned for their multifaceted physical characteristics and versatile applications, particularly in optoelectronics. In detection applications, a low and stable dark current is crucial, enhancing the sensitivity and signal‐to‐noise ratio of detectors. Herein, a van der Waals layered material has synthesized, CuInP2Se6. Despite its nanometric scale, 2D CuInP2Se6 detector transcends the conventional absorption inefficiencies tied to ultrathin materials. It delivers exceptional ultraviolet–visible detection, characterized by an ultralow, stable dark current of 150 fA, and a noise power density of 27.7 fA Hz−1/2 at room temperature. The in‐depth investigation reveals a responsivity of 4.47 A W−1, an external quantum efficiency of 1369%, a special detectivity of 1.44 × 1013 Jones, and a rapid response speed of 280 µs, positioning it at the pinnacle of 2D photodetector performance. The CuInP2Se6’s ultralow, stable dark current paves the way for X‐ray detection, achieving an unprecedented sensitivity of 1.32 × 105 µC Gyair−1 cm−2 and a low detection limit of 0.15 µGyair s−1. Furthermore, 2D CuInP2Se6 detector exhibits a remarkable image‐sensing capability, adeptly capturing intricate patterns with high resolution. This discovery indicates its promise in revolutionizing integrated micro/nano optoelectronic devices, opening avenues for advancements in light and X‐ray detection and imaging technologies. [ABSTRACT FROM AUTHOR]