Ultrasensitive and Broad‐Spectrum Photodetectors Based on InSe/ReS₂ Heterostructure

Abstract Photogating effect based on vertical structure of 2D materials allows for the realization of a highly sensitive photodetector. A highly sensitive and broad‐spectrum (365–965 nm) photodetector is reported based on the indium selenide (InSe)/rhenium disulfide (ReS₂) vertical heterostructure, where the top layer InSe serves as the photogate to regulate the channel current, enabling a large photoconductive gain of 10⁶. The detectivity of the photodetector can reach 6.51 × 10¹³ Jones, making this one of the highest values among reported transition metal dichalcogenide photodetectors. The photodetector represents a high responsivity of 1921 A W⁻¹, an ultrahigh external quantum efficiency (EQE) of 6.53 × 10⁵%, and a fast response time of 21.6 ms. The outstanding properties of the InSe/ReS₂ heterojunction reveal the promising potential in high‐efficient, ultrasensitive, broadband photodetectors.