Effects of deposition parameters on structures and photoluminescence of MoO_(3-x) nanomaterials grown by CVD

摘要

MoO3-x, nanomaterials were synthesized on Si substrate deposited with gold film in hot filaments assisted chemical vapor deposition system using low cost precursors MoO3 and N-2. The characterization results indicate that the structures of MoO3-x nanomaterials transfer from nanoparticles to nanosheets with the reduction of N-2 flow rate and growth time, which results from the weakening diffusion of MoO3-like molecules in gas environment. Furthermore, the photoluminescence (PL) of MoO3-x nanomaterials was studied at room temperature. The PL results indicate that the MoO3-x, nanomaterials emit ultraviolet, blue, green, red and near-infrared light, and the MoO3-x, nanosheets generate stronger PL emission than the MoO3-x nanoparticles. These multi-PL bands are related to the bandgap of MoO3, the transition between the sub-bands related to Mo5+ defects and oxygen vacancies, and the transition between the intermediate and valence bands, respectively. The strong PL emission of MoO3-x nanosheets is associated with the enhancement of oxygen vacancies due to more surfaces and edges of nanosheets. Our results provide an effective method of controlling the structures of molybdenum oxide nanomaterials and contribute to the development of next-generation optoelectronic devices based on molybdenum oxide nanomaterials.