High-performance broadband photodetector based on PtSe2/MoS2 heterojunction from visible to near-infrared region

Broadband photodetectors based on narrow bandgap 2D materials have garnered considerable interest for application in the field of optoelectronic devices. However, their large dark current hinders device performance. In this work, a PtSe2/MoS2 heterojunction was fabricated for a broadband photodetector operating within the range of visible to near-infrared. The device exhibited suppressed dark currents with a high rectification ratio of 104. The built-in electric field of the heterojunction promoted carrier separation effectively, and the device achieved excellent photoelectric performance with responsivities of 1.7 x 103, 27.52, and 21 mA/W at 635, 785, and 1550 nm wavelengths, respectively. Moreover, the specific detectivities (D*) were 2.2 x 1013 Jones (635 nm), 3.55 x 1011 Jones (785 nm), and 2.72 x 108 Jones (1550 nm). The device demonstrated a rise/fall time of 131/241 mu s under 1550 nm laser illumination. Visible and near-infrared imaging detection was also demonstrated based on the heterojunction device at room temperature. This work sheds light on the remarkable potential of PtSe2/MoS2 heterojunctions in the domain of high-performance broadband photodetectors.