Photosensitivity of bulk and monolayer MoS2-based two-terminal devices

Abstract

Transition metal dichalcogenides (TMDCs), such as MoS2, MoSe2, WS2, and WSe2, have attracted enormous attention owing to their unique electrical and optical properties. A type of material known as TMDC has the MX2 formula with a direct bandgap in ultra-thin layers and indirect bandgap properties in the bulk. TMDCs have attracted significant research interest due to their use in nano-devices, opto-electronics, and next-generation electronics. In the study, two different MoS2 devices, Au-bulk MoS2-Au and Au-monolayer MoS2-Au, were fabricated, and their photon-induced current-voltage characteristics at different wavelengths (red approximate to 650 nm, green approximate to 532 nm and blue approximate to 450 nm) and values were compared. Additionally, the time-dependent photoresponses of these devices under red light irradiation (wavelength, lambda(ex) = 650 nm) were analyzed. The Au-monolayer MoS2-Au device had a higher current response compared with the Au-bulk MoS2-Au device. These results suggest that single-layer MoS2 devices could be more efficient and responsive than bulk MoS2 devices for a variety of applications.