Canonical RETe3 (RE = Rare‐Earth Elements) with Charge Density Wave for Room Temperature Self‐Powered Photodetectors Spanning Mid‐Wave Infrared Band

Abstract Charge density wave (CDW), as an ordered electronic state, typically leads to the opening of a narrow bandgap, which can be excited by relatively low‐energy photons, such as infrared light. Compounds with CDW, therefore, hold significant potential for high‐performance broadband photodetectors. In this work, rare‐earth tritellurides ( RE Te 3 , where RE = La, Ce, Pr, Nd, Sm, and Dy), a well‐known series with CDW transitions above room temperature, are investigated for the first time for room‐temperature, broadband, and self‐powered photodetection. RE Te 3 ‐based photodetectors demonstrate a broadband response spanning 380 to 4400 nm, covering the ultraviolet to mid‐wave infrared range. Notably, the DyTe 3 ‐based photodetector achieves a responsivity of 27 mA W −1 at 3500 nm in the mid‐wave infrared region, with a detectivity of 1.26 × 10 9 Jones and a response time of 78 ms, comparable to photodetectors dominated by the photothermoelectric effect based on graphene. This work establishes RE Te 3 as a promising new family for low‐power, room‐temperature, and broadband photodetection applications.