Junction Field-Effect Transistors Based on PdSe2/MoS2 Heterostructures for Photodetectors Showing High Responsivity and Detectivity

2D materials have shown great promise for next-generation high-performance photodetectors. However, the performance of photodetectors based on 2D materials is generally limited by the tradeoff between photoresponsivity and photodetectivity. Here, a novel junction field-effect transistor (JFET) photodetector consisting of a PdSe₂ gate and MoS₂ channel is constructed to realize high responsivity and high detectivity through effective modulation of top junction gate and back gate. The JFET exhibits high carrier mobility of 213 cm² V⁻¹ s⁻¹. What is more, the high responsivity of 6 × 10² A W⁻¹, as well as the high detectivity of 10¹¹ Jones, are achieved simultaneously through the dual-gate modulation. The high performance is attributed to the modulation of the depletion region by the dual-gate, which can effectively suppress the dark current and enhance the photocurrent, thereby realizing high detectivity and responsivity. The JFET photodetector provides a new approach to realize photodetectors with high responsivity and detectivity.