With the increasing demand for multispectral information acquisition, infrared multispectral imaging technology that is inexpensive and can be miniaturized and integrated into other devices has received extensive attention. However, the widespread usage of such photodetectors is still limited by the high cost of epitaxial semiconductors and complex cryogenic cooling systems. Here, we demonstrate a noncooled two-color infrared photodetector that can provide temporal-spatial coexisting spectral blackbody detection at both near-infrared and mid-infrared wavelengths. This photodetector consists of vertically stacked back-to-back diode structures. The two-color signals can be effectively separated to achieve ultralow crosstalk of ~0.05% by controlling the built-in electric field depending on the intermediate layer, which acts as an electron-collecting layer and hole-blocking barrier. The impressive performance of the two-color photodetector is verified by the specific detectivity (D*) of 6.4 × 109 cm Hz1/2 W−1 at 3.5 μm and room temperature, as well as the promising NIR/MWIR two-color infrared imaging and absolute temperature detection.

This review focuses on the existing strategies and underlying mechanisms, and discusses future directions in epitaxial substrate engineering to deliver wafer-scale 2D materials for integrated electronics and photonics.

The preparation of ternary 2D layered material (2DLM) FePSe3 and field‐effect transistor (FET) type photodetector are investigated. By advancing an optimized chemical vapor transport method, bulk crystal FePSe3 is synthesized within several growth hours instead of routinely required weeks, from which 2DLM FePSe3 flakes with a thickness of ≈22.0 nm and high crystalline quality are obtained through mechanical exfoliation. Ohmic contacts for FET structure with good linear conductivity and thermal stability are implemented through the combination of electron‐beam lithography and thermal evaporation techniques. Transfer characteristics prove the p‐type conductivity of the 2DLM FePSe3 channel. The transistor devices exhibit good performance at 637 nm with a detectivity of 1.17 × 107 Jones. More importantly, a wide photocurrent spectrum from visible (450 nm) to near‐infrared (940 nm) of ternary 2DLMs is observed, which is attributed to the improvement of crystal quality of 2DLM, relatively low surface defect states, and high‐performance Ohmic electrodes. This work promotes the development of ternary 2DLM and photodetector that are still in their infancy towards continuous broad‐spectrum technology.