Annealing Temperature Effect on the Surface Properties of the MoSe Thin Films

Abstract

2D transition metal dichalcogenides have been studied extensively in the field of electronics and photonics. Among them, the molybdenum chalcogenides have been receiving considerable attention due to their potential usage in field‐effect transistors and biosensors. Despite such promising aspects of these materials, studies regarding temperature effects on MoSe remain relatively rare. Herein, MoxSey (x = 0 ≈ 10, y = 0 ≈ 2) thin films are fabricated by radio frequency (RF) magnetron cosputtering on silicon and investigated using scanning electron microscopy for various atomic ratios and annealing temperatures from room temperature to 500 °C. Above the melting point of Se, Se evaporates and forms a layer, subsequently leading Mo to be exposed on the surface of the thin films. From the X‐ray diffraction and X‐ray photoelectron spectroscopy results, silicon peaks are observed due to the evaporation of Se. In addition, both Mo and Se are oxidized at above 300 °C. The work functions of the MoxSey thin films show the highest value at 200 °C measured by ultraviolet photoelectron spectroscopy and a Kelvin probe. Above the melting point of Se, there is a tendency for the work function to decrease due to the influence of Mo.