Blackbody‐Sensitive Uncooled Infrared Detector with Ultra‐Broadband and Ultrafast Photoresponse Based on Te/WTe2 Heterostructure

Abstract Blackbody‐sensitive uncooled infrared photodetectors with ultra‐broadband and ultrafast photoresponse have a profound impact on many areas of modern science and technology. However, it is a big challenge for both traditional photodetectors and emerging low‐dimensional ones to simultaneously have all the above characteristics. Here, this challenge is addressed by establishing a Te/WTe 2 heterostructure photodetector. The built‐in field of the heterostructure and the crossing conduction and valence bands of WTe 2 jointly result in a high responsivity and a visible‐to‐long‐wavelength‐infrared photoresponse range. The peak responsivity (at the 3.3 µm wavelength) reaches 914 mA W −1 at zero bias and 8.51 A W −1 at 2 V bias. Further, the joint action coupled with the high mobility of Te and WTe 2 promotes the 3‐dB bandwidth to 153 kHz. The self‐powered blackbody responsivity and specific detectivity reach 235.7 mA W −1 and 1.1 × 10 8 cm Hz 1/2 W −1 , respectively. The former increases to 5.82 A W −1 at 1 V bias. Moreover, this device is polarization‐sensitive with a contrast ratio of 2. This work reveals the potential of the Te/WTe 2 heterostructure for high‐performance room‐temperature infrared photodetectors.