Design of 2D Layered PtSe₂ Heterojunction for the High-Performance, Room-Temperature, Broadband, Infrared Photodetector

The rich variety and attractive properties of two-dimensional (2D) layered nanomaterials provide an ideal platform for fabricating next generation of advanced optoelectronic devices. Recently, a newly discovered 2D layered PtSe2 thin film has exhibited outstanding broadband sensitivity and optoelectronic properties. In our work, a large-area 2D layered PtSe2 thin film was used to construct the PtSe2/CdTe heterojunction infrared photodetector (PD). This PD exhibited a broad detection range coverage from 200 to 2000 nm with a high responsivity of 506.5 mA/W, a high specific detectivity of 4.2 × 1011 Jones, a high current on/off ratio of 7 × 106, and a fast response speed of 8.1/43.6 μs at room temperature. Additionally, the PtSe2/CdTe heterojunction PD exhibits excellent repeatability and stability in air. The high-performance of the PtSe2/CdTe heterojunction PD demonstrated in this work reveals that it has great potential to be used for broadband infrared detection.