Broad spectrum UV–Vis-NIR photodetector based on mechanically exfoliated MoSSe thin film

Abstract

In recent years, binary transition metal dichalcogenides (TMDs) have emerged as a highly promising class of optoelectronic materials, due to their exceptional stability and optoelectronic properties. However, binary TMDs are typically associated with deep defect states, impeding the enhancement of the device's photo responsivity and response time. The alloying of binary two-dimensional (2D) materials provides an effective solution to this problem. A broadband metal-semiconductor-metal (MSM) photodetector based on a mechanically exfoliated MoSSe thin film is reported. The device shows excellent responsivity and fast response at UV–Vis-NIR wavelengths (375–1550 nm). Under the irradiation of the 532 nm laser, the device shows a photo responsivity (R) of 15 mA/W, a specific detectivity (D₁*) of 6.91 × 10⁹ Jones and D₂* of 6.48 × 10⁹ Jones, a response rise time of 43 ms, and a fall time of 38 ms. Moreover, the photoelectric imaging of a photodetector at 1550 nm was achieved by a single-site scanning imaging system. This research has contributed to the field of 2D materials, particularly in MoSSe for broadband photodetectors and photoelectric imaging.