Thin-layered materials from transition-metal dichalcogenides family and their preforms such as molybdenum three oxides (MoO3) exhibit great potential as active material in optoelectronics. Stable materials of few atoms thick have shown emerging capabilities in this area. In this article, we report the synthesis of MoO3 nanostructures by spray pyrolysis method. We will, perhaps for the first time, show that by varying the hot plate temperature from 350 to 4400C, a phase transformation reveal from h-MoO3 to α-MoO3. By annealing the prepared α-MoO3 sample a preferential orientation of (002) crystal plane is induced. A large band gap of 2.8 eV for the prepared MoO3 film was obtained from the transmission spectra. The Raman vibrational modes were investigated for excitation wavelength at 532 nm using MoO3 films and for a heterostructured MoO3/MoS2 film .Better crystallinity and decrease in defects intensity, as an advantage of MoO3 hybridization can be achieved by proper fabricating the heterostructure sample. Manuscript profile

AbstractThe synthesis of ultra-long high-quality zinc sulfide (ZnS) nanowires of uniform size on heterogeneous substrates is highly desirable for investigating the fundamental properties of ZnS nanowires and for fabricating integrated functional nanodevices. The present study developed a novel technique for growing ultra-long ZnS nanowires on thin-catalyst-coated substrates. ZnS nanowires were synthesized by chemical vapor deposition on a silicon substrate deposited by gold (~ 5 nm in thickness) as the catalyst at 550, 600, 700, 750 and 800 °C. The structural properties of the samples were investigated by X-ray diffraction, and the results showed that the fabricated nanowires have both wurtzite and zinc blend structures. The morphological properties of the nanowires were determined by scanning electron microscopy, and the results show that the substrate is thoroughly coated with 10 µm of zinc sulfide nanowires. Increasing the substrate temperature from 600 to 800 °C increased the diameter of the nanowires and decreased the length. The growth mechanism of the nanowires was vapor–liquid–solid. The EDX spectra of this sample showed an absence of contamination, confirming the high purity of the ZnS nanowires. Manuscript profile