Enhanced Perovskite Film Quality and Hole Transport through V₂CT_x MXene Modulation for Self-Powered CsPbCl₃ UV Photodetectors

Enhancement of the perovskite film quality and charge transfer capability is crucial for enhancing device performance. The all-inorganic CsPbCl 3 perovskite, which shows great potential as an absorber layer in ultraviolet photodetectors (UV PDs), has been hindered by poor material stability and high interface states, limiting its widespread application. In this work, the quality of the CsPbCl 3 films and the perovskite/Au electrode interface were synergistically modulated using V 2 CT x MXene. After additive (CsPbCl 3 @V 2 CT x ) and interface (CsPbCl 3 /V 2 CT x ) engineering, the optimal properties of CsPbCl 3 films and the van der Waals (vdW) bonding of V 2 CT x strengthen the charge extraction and hole transport while reducing nonradiative charge recombination caused by internal defects and interface states. Ultimately, the UV PD featuring the FTO/SnO 2 /CsPbCl 3 @V 2 CT x /V 2 CT x /Au structure manifests outstanding performance under the self-powered mode, attaining an extremely high responsivity of up to 1.01 × 10 3 mA/W and a considerable specific detectivity of 5.46 × 10 11 cm Hz 1/2 /W (365 nm, 0.16 mW/cm 2 ) coupled with a swift rise/decay time of 1.54/1.50 μs. Even after 30 days under an air atmosphere, the responsivity of the device remains at 8.46 × 10 2 mA/W, indicating extraordinary stability. This approach offers a novel way to enhance the performance of UV PD based on the CsPbCl 3 perovskite through the dual strategy of V 2 CT x MXene modulation.