ABSTRACT
Unique properties possessed by transition metal dichalcogenides (TMD) attract much attention to investigation of their formation and dependence of their characteristics on the production process parameters. Here we investigate formation of TMD films during chemical vapor deposition (CVD) in the mixture of the thermally activated gaseous H2S and vaporized transition metals. Our observations of changes in morphology, Raman spectra, and photoluminescent (PL) properties in combination with in-situ measurements of electrical conductivity of the deposits formed at various precursors concentrations and CVD duration are evidencing on existence of particular stages in the TMD materials formation. Gradual transformation of PL spectra from trion to exciton type is detected for different stages of the material formation. Obtained results and proposed methods provide tailoring of TMD film characteristics demanded for the particular applications like photodetectors, photocatalyst, gas sensors.
