The growth of tungsten ditelluride (WTe2) thin films on c-plane sapphire substrates was demonstrated by metalorganic chemical vapor deposition (MOCVD) using tungsten hexacarbonyl (W(CO)6) and diethyltelluride (DETe) as precursors for W and Te, respectively, in a H2 carrier gas. The effects of substrate temperature, reactor pressure, precursor and carrier gas flow rates, and chalcogen-to-metal ratio on the WTe2 growth rate and film properties were determined. Substrate temperatures less than 500 °C were required to deposit WTe2 which was found to be beneficial to suppress simultaneous carbon deposition from the DETe precursor. The films exhibited a fine-grained morphology independent of growth temperature. The layered crystalline 1 T’ phase of WTe2 was confirmed using high resolution X-ray diffraction (HRXRD) and cross-sectional transmission electron microscopy (TEM) which revealed that the films were predominantly c-axis oriented with in-plane twist. X-ray photoelectron spectroscopy (XPS) demonstrated that the WTe2 films were stable in air for a few days but eventually exhibited oxidation.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Inorganic Chemistry
- Materials Chemistry