Direct Growth of Low Thermal Conductivity WTe₂ Nanocrystalline Films on W Films

WTe₂ has attracted much attention because of its layered structure and special electronic energy band structure. However, due to the difficulty of evaporating the W element itself and the inactivity of the Te element, the obtained large-area WTe₂ thin films are usually accompanied by many defects. In this paper, WTe₂ nanocrystalline films were successfully prepared on quartz substrates using magnetron sputtering and chemical vapor deposition techniques. Various analytical techniques such as X-ray Diffraction, Raman spectra, X-ray Photoelectron Spectroscopy, Scanning Electron Microscope, and photoluminescence spectra are employed to analyze the crystal structure, composition, and morphology. The effects of different tellurization temperatures and tellurization times on the properties of WTe₂ thin films were investigated. WTe₂ nanocrystalline films with good crystallinity were obtained at 600 °C for 30 min. The thermal conductivity of the WTe₂ films prepared under this condition was 1.173 Wm^-1K^-1 at 300 K, which is significantly higher than that of samples prepared using other methods.