Ultrabroadband photoresponse based on Te/SnS₂ heterojunction with fast speed

Abstract Tellurium, a two-dimensional (2D) p-type semiconductor with a narrow bandgap and notable carrier mobility, has garnered significant research attention for polarization-sensitive infrared photodetectors. In this work, we present a wide-spectrum photodetector constructed from the 2D van der Waals p–n heterojunction Te/SnS 2 . This device demonstrates a broadband photodetection capability ranging from 275 nm (solar-blind ultraviolet, SBUV) to 10.6 μ m (long-wave infrared, LWIR). Under SBUV illumination, it achieves a high responsivity ( R ) of 317.0 AW −1 and exhibits a minimal noise equivalent power ( NEP ) of 2.7 × 10 −13 WHz −1/2 . In the visible range, the device shows rapid photoresponse characteristics with a rise time ( τ r ) of 0.62 μ s and a decay time ( τ d ) of 0.66 μ s, along with polarization sensitivity characterized by a dichroic ratio of approximately 1.32. Remarkably, the device also demonstrates strong LWIR detection performance at room temperature, with a responsivity of 57.9 mAW −1 and a NEP of 8.9 × 10 −11 WHz −1/2 . These results suggest a novel approach to designing advanced polarization-resolving photodetectors using anisotropic 2D materials.