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The high-performance broadband photodetectors have attracted intensive scientific interests due to their potential applications in optoelectronic systems. Despite great achievements in two-dimensional (2D) materials based photodetectors such as graphene and black phosphorus, obvious disadvantages such as low optical absorbance and instability preclude their usage for the broadband photodetectors with the desired performance. An alternative approach is to find promising 2D materials and fabricate heterojunction structures for multifunctional hybrid photodetectors. In this work, 2D WS2/Si heterojunction with a type-II band alignment is formed in situ. This heterojunction device produced a high Ion/Ioff ratio over 10,6 responsivity of 224 mA/W, specific detectivity of 1.5 × 1012 Jones, high polarization sensitivity, and broadband response up to 3043 nm. Furthermore, a 4 × 4 device array of WS2/Si heterojunction device is demonstrated with high stability and reproducibility. These results suggest that the WS2...

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.