Two-step growth of VSe₂ films and their photoelectric properties

We put forward a two-step route to synthesize vanadium diselenide (VSe₂), a typical transition metal dichalcogenide (TMD). To obtain the VSe₂ film, we first prepare a vanadium film by electron beam evaporation and we then perform selenization in a vacuum chamber. This method has the advantages of low temperature, is less time-consuming, has a large area, and has a stable performance. At 400 ^circC selenization temperature, we successfully prepare VSe₂ films on both glass and Mo substrates. The prepared VSe₂ has the characteristic of preferential growth along the c-axis, with low transmittance. It is found that the contact between Al and VSe₂/Mo is ohmic contact. Compared to Mo substrate, lower square resistance and higher carrier concentration of the VSe₂/Mo sample reveal that the VSe₂ film may be a potential material for thin film solar cells or other semiconductor devices. The new synthetic strategy that is developed here paves a sustainable way to the application of VSe₂ in photovoltaic devices.