2D Perovskite Single‐Crystalline Photodetector with Large Linear Dynamic Range for UV Weak‐Light Imaging

Abstract Weak‐light imaging holds immense significance in various imaging applications. Recently, there has been significant research focused on 2D perovskites for photodetectors (PDs), owing to their superior photoelectric properties. However, the utilization of 2D perovskites for high‐performance weak‐light detection remains limited, and there is a notable absence of demonstration in weak‐light ultraviolet (UV) imaging. Herein, a high‐sensitive UV detectors with an ultra‐low detection limit for weak‐light imaging are demonstrated, utilizing 2D perovskite (PA) 2 PbBr 4 (PPB) single crystals (SCs). Leveraging the exceptional quality of SCs, the PPB‐based PD exhibits outstanding operational performances, including a low dark current of 0.735 pA, high on/off ratio of 4150 under 263.3 mW cm −2 illimitation, and extensive linear dynamic range of 153.61 dB, which is currently the highest reported value among 2D perovskite SC detectors. Notably, PPB PDs demonstrate a remarkable response under 5.49 nW cm −2 illumination, enabling it to exhibit outstanding photo‐response with an excellent detectivity of 2.3 × 10 13 Jones and responsivity of 2.22 A W −1 . Importantly, high‐resolution images are successfully obtained under weak‐light illumination. These findings underscore the immense potential of 2D perovskite for UV weak‐light imaging.