Van der Waals integration of phase-pure 2D perovskite sheets and GaAs nanowires for self-driven photodetector†

Semiconductor heterostructures hold significant importance for exploring novel functional optoelectronic devices, but the chemical instability and soft lattice framework of perovskites significantly hinder the efficient heterogeneous integration with other perovskite or semiconductor materials. Herein, based on the large-area phase-pure 2D perovskite sheets, a BA₂MA₂Pb₃I₁₀/GaAs van der Waals (vdW) heterostructure has been successfully constructed. The favorable vdW contacts allow the device to be cut-off at forward bias with a remarkably low dark current of 1.94 pA. This endows the heterostructure device with excellent detection performance, achieving a linear dynamic range of 80.9 dB and a detectivity of 6.17 × 10¹⁰ Jones. Additionally, the interfacial potential of the heterostructure enables the device to operate in a self-driven manner across broad spectral ranges from ultraviolet to near-infrared. Our study demonstrates efficient vdW integration based on perovskite and provides a new foundation for constructing perovskite vdW heterostructures.