Ternary FePSe 3 Atomic Layers with Competitive Temperature Coefficient of Resistance for Uncooled Infrared Bolometers

The semiconducting metal phosphorus trichalcogenides (MPX 3 , X = S, Se), a new family of layered atomic materials similar to the transition‐metal dichalcogenides, have recently attracted great attention owing to their 2D magnetic properties as well as their wide range of tunable bandgaps, which can lead to promising applications in spintronic and optoelectronic devices. Herein, an uncooled bolometer based on FePSe 3 atomic layers is reported, on which a competitive temperature coefficient of resistance (TCR) of ≈−2.96% K −1 at room temperature is observed. In detecting infrared radiation (980–1550 nm) at room temperature using the FePSe 3 bolometer, high responsivity exceeding 10 8 V W −1 and specific detectivity up to 10 9 Jones are achieved, which can be attributed to the combined advantages of the competitive room‐temperature TCR and natural thermal isolation between the inner layers of FePSe 3 and the environment. This result reveals a remarkable property of FePSe 3 atomic layers and paves the way toward new types of bolometers with high sensitivities.