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

Abstract 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, CuInP 2 Se 6 . Despite its nanometric scale, 2D CuInP 2 Se 6 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 × 10 13 Jones, and a rapid response speed of 280 µs, positioning it at the pinnacle of 2D photodetector performance. The CuInP 2 Se 6 ’s ultralow, stable dark current paves the way for X‐ray detection, achieving an unprecedented sensitivity of 1.32 × 10 5 µC Gy air −1 cm −2 and a low detection limit of 0.15 µGy air s −1 . Furthermore, 2D CuInP 2 Se 6 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.