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

Emerging low-dimensional materials exhibit thepotential in realizing next-generation room-temperature black-body-sensitive infrared detectors. As a narrow band gap semi-conductor, low-dimensional tellurium (Te) has been a focus ofinfrared detector research attention because of its high holemobility, large absorptivity, and environmental stability. However,it is still a challenge to fabricate blackbody-sensitive Te-basedinfrared detectors with a low dark current and fast speed. In thiswork, a heterojunction device based on Te and graphene isconstructed, achieving high detectivity and a fast response timefrom visible to mid-infrared. Specifically, under 2 mu m laserirradiation, the heterojunction photodetector exhibits a detectivity of 1.04x109cm Hz1/2W-1, a fast response time of 28 mu s,and good ambient stability. Moreover, the photodetector demonstrates a room-temperature blackbody sensitivity with the peakdetectivity of up to 3.69x108cm Hz1/2W-1under zero bias. Linear array devices are further explored and show good performanceuniformity for potential imaging applications. Our work demonstrates that the Te/graphene heterojunction detector will be one ofthe competitive candidates for next-generation uncooled blackbody-sensitive infrared photodetectors