Cl‐Terminated Mo4/3B2‐x MBene‐Modulated CsPbCl3 Perovskite for Enhanced‐Performance Self‐Powered UV Photodetectors Enabling Efficient Large‐Area Imaging

Abstract High‐performance and long‐term stability of perovskite‐based ultraviolet photodetectors (UV PDs) are two critical prerequisites for their fully mature applications. The preparation of high‐crystallinity perovskite films with controlled defect density and enhanced environmental resistance has emerged as an effective strategy to address this challenge. This study proposes the incorporation of a functionalized novel 2D material, Cl‐terminated Mo 4/3 B 2‐ x MBene (Mo 4/3 B 2‐ x Cl z ), to improve the quality of the CsPbCl 3 films. Mo 4/3 B 2‐ x Cl z serves as an efficient permeation channel, facilitating the reaction between the precursor solutions and enhancing the crystallinity of the films. Furthermore, the surface terminations of Mo 4/3 B 2‐ x Cl z establish a strong coupling effect with the uncoordinated Pb 2+ ions while simultaneously passivating the chlorine vacancy. This dual functionality effectively reduces the trapstate density and enhances the stability of the perovskite films. Ultimately, the UV PD treated with Mo 4/3 B 2‐ x Cl z achieves a responsivity of 1.1 × 10 3 mA W −1 , a specific detectivity of 7.3 × 10 12 cm Hz 1/2 W −1 , along with a rapid rise/decay time of 0.53/0.48 µs under self‐powered mode, demonstrating outstanding long‐term stability and successful application in large‐area imaging. This research offers significant insights into the functionalization of MBene and highlights its pivotal role in the development of high‐performance PDs for advanced UV imaging applications.