UC Davis

Transition Metal Dichalcogenides (TMDCs) are strong candidates for a new class ofsemiconductors due to their tunable bandgaps. Their capacity to stretch and deform makes them suitable for various medical sensors, and TMDCs can be engineered to have thicknesses as low as 1 nm. Despite their potential, producing TMDCs on an industrial scale remains challenging with the current chemical vapor deposition (CVD) methods. The issues stem from the inability to rapidly produce them and the difficulty in maintaining consistency due to multiple sensitive parameters like temperature, pressure, and precursor quantity. A promising alternative is a twostep method, which begins with the sputtering of the transition metal before the CVD process. This approach streamlines the TMDC production process, minimizing variables by automating one of the precursor stages and eliminating the need for manual intervention and catalysts. It's also vital to explore other transition metals since these can alter the TMDCs' properties, particularly their magnetic and superconductive characteristics. In this study, samples were generated using a metal seeding layer method with single coatings of Tungsten and Molybdenum. Dual coatings, including Titanium coated with Molybdenum and Chromium coated with Molybdenum, were tested to inhibit oxidation in the TMDCs. Each sample underwent comprehensive analysis at both the compositional and structural levels including. Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and atomic force microscopy (AFM). Whereas Molybdenum disulfide and Tungsten disulfide showed experimental data consistent with the existence of sulfide phases, other materials lack evidence of such sulfurization. The AFM data revealed that the Tungsten disulfide displayed a triangular structure, which is characteristic of this material. While further research on sulfurization of Titanium and Chromium is required, the two-step synthesis approach showed the potential for broader class of 2D materials including Nickel, Niobium, Vanadium, and more to determine if the metal seeding approach is universally applicable to all TMDCs.