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 WS 2 /Si heterojunction with a type-II band alignment is formed in situ. This heterojunction device produced a high I on /I off ratio over 10, 6 responsivity of 224 mA/W, specific detectivity of 1.5 × 10 12 Jones, high polarization sensitivity, and broadband response up to 3043 nm. Furthermore, a 4 × 4 device array of WS 2 /Si heterojunction device is demonstrated with high stability and reproducibility. These results suggest that the WS 2 /Si type-II heterojunction is an ideal photodetector in broadband detection and integrated optoelectronic system.

The research of ultraviolet photodetectors (UV PDs) have been attracting extensive attention, due to their important applications in many areas. In this study, PtSe 2 /GaN heterojunction is in-situ fabricated by synthesis of large-area vertically standing two-dimensional (2D) PtSe 2 film on n-GaN substrate. The PtSe 2 /GaN heterojunction device demonstrates excellent photoresponse properties under illumination by deep UV light of 265 nm at zero bias voltage. Further analysis reveals that a high responsivity of 193 mA•W-1 , an ultrahigh specific detectivity of 3.8 × 10 14 Jones, linear dynamic range of 155 dB and current on/off ratio of ~ 10 8 , as well as fast response speeds of 45/102 μs were obtained at zero bias voltage. Moreover, this device response quickly to the pulse laser of 266 nm with a rise time of 172 ns. Such high-performance PtSe 2 /GaN heterojunction UV PD demonstrated in this work is far superior to previously reported results, suggesting that it has great potential for deep UV detection.

Self-powered MoS2/GaN p–n heterojunction photodetectors exhibited high sensitivity to deep-UV light with high responsivity, specific detectivity and fast response speeds.

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.

High-performance self-powered solar-blind photodetector based on a MoS2/β-Ga2O3 heterojunction was demonstrated, which exhibits excellent solar-blind photoresponse properties.