High-Temperature Coefficient of Resistance in Mo_xW_1−xS₂ Thin Film

Abstract

Despite the use of transition metal dichalcogenides being widespread in various applications, the knowledge and applications of MoxW1−xS2 compounds are relatively limited. In this study, we deposited a MoW alloy on a Si substrate using a sputter system. Consequently, we successfully utilized a furnace to sulfurize the MoW alloy from 800 to 950 °C, which transferred the alloy into a MoxW1−xS2 ternary compound. The Raman spectra of the MoxW1−xS2 samples indicated an additional hybridized Raman peak at 375 cm−1 not present in typical MoS2 and WS2. With increasing sulfurization temperature, the scanning electron microscopy images revealed the surface morphology of the MoxW1−xS2 gradually becoming a sheet-like structure. The X-ray diffraction results showed that the crystal structure of the MoxW1−xS2 tended toward a preferable (002) crystal orientation. The I–V results showed that the resistance of MoxW1−xS2 increased when the samples were sulfurized at a higher temperature due to the more porous structures generated within the thin film. Furthermore, a high-temperature coefficient of resistance for the MoxW1−xS2 thin film sulfurized at 950 °C was about −1.633%/K−1. This coefficient of resistance in a MoxW1−xS2 thin film indicates its suitability for use in thermal sensors.

Keywords

• 2D
• sulfurization
• temperature coefficient of resistance
• thermal sensor