Room-Temperature Blackbody-Sensitive and Fast Infrared Photodetectors Based on 2D Tellurium/Graphene Van der Waals Heterojunction

Emerging low-dimensional materials exhibit the potential in realizing next-generation room-temperature blackbody-sensitive infrared detectors. As a narrow band gap semiconductor, low-dimensional tellurium (Te) has been a focus of infrared detector research attention because of its high hole mobility, large absorptivity, and environmental stability. However, it is still a challenge to fabricate blackbody-sensitive Te-based infrared detectors with a low dark current and fast speed. In this work, a heterojunction device based on Te and graphene is constructed, achieving high detectivity and a fast response time from visible to mid-infrared. Specifically under 2 μm laser irradiation, the heterojunction photodetector exhibits a detectivity of 1.04 × 10⁹ cm Hz^1/2 W⁻¹, a fast response time of 28 μs, and good ambient stability. Moreover, the photodetector demonstrates a room-temperature blackbody sensitivity with the peak detectivity of up to 3.69 × 10⁸ cm Hz^1/2 W⁻¹ under zero bias. Linear array devices are further explored and show good performance uniformity for potential imaging applications. Our work demonstrates that the Te/graphene heterojunction detector will be one of the competitive candidates for next-generation uncooled blackbody-sensitive infrared photodetectors.