Self‐Powered Broadband UV–NIR Photodetectors Based on InSe/PtS₂ Van der Waals Heterostructure

Abstract Van der Waals heterostructures (vdWHs) consisting of 2D materials offer a practical and effective approach for engineering multifunctional, high‐performance photodetectors. However, 2D vdWHs photodetectors based on photoconductive effects require an external power input and are often accompanied by a large dark current, which hinders the development of miniaturization and portability of devices and greatly limits the application of devices in complex environments. Herein, a self‐powered photodetector constructed from an InSe/PtS₂ vdWH with an extremely low dark current (≈10⁻¹⁴ A) at zero bias and a large rectification ratio of 5.1 × 10³ is reported. Leveraging the robust built‐in electric field of the InSe/PtS₂ vdWH, the device demonstrates pronounced photovoltaic effects, characterized by an open‐circuit voltage of 0.395 V and a substantial short‐circuit current of 37.1 nA. Remarkably, a high responsivity and detectivity of 211 mA W⁻¹ and 8.58 × 10¹² Jones, an excellent light on/off ratio of 0.8 × 10⁷ , and a fast response time of 465/470 µs are achieved, at zero bias. The device showcases a broadband self‐powered photoresponse spanning from 265 to 1064 nm. This study demonstrates the high potential of the InSe/PtS₂ vdWH for broadband self‐powered photodetector applications.