Tailored structure and photoluminescence of substoichiometric molybdenum oxide nanomaterials by doping of gallium oxide

Abstract Substoichiometric molybdenum oxide (MoO3-x) nanomaterials become the promising structure-dependent semiconductor materials. However, the structural tuning of MoO3-x nanomaterials is still an important challenge. Here we report the tuned MoO3-x nanostructures via the doping of Ga2O3 in hot filament chemical vapor deposition system. The diverse characterization results indicate that the addition of Ga2O3 in the MoO3 precursor leads to the doping of Ga2O3 in the MoO3-x nanostructures and the increase of the MoO2 component in MoO3-x nanomaterials. Furthermore, the addition of Ga2O3 improves the regularity of MoO3-x nanoparticles (NPs) and induces the lattice expansion of MoO3-x nanostructures. The photoluminescence (PL) properties were measured at room temperature. The PL results exhibit that the synthesized MoO3-x nanomaterials generate the ultraviolet, blue, green, red and near infrared light due to the bandgap transition, the transition between two sub-bands, the intervalence charge transfer transition and the transition from the intermediate level to valence band, respectively. In addition, the PL results also reveal the PL quenching due to the doping of Ga2O3, which is related to the reduction of nanocavities, the aggregation of the MoO3-x NPs and the increase of MoO2 phase induced by the incorporation of Ga2O3 in the MoO3-x nanostructures. These achievements can contribute to the tuning of MoO3-based nanostructures and the development of next-generation optoelectronic nanodevices based on doping-engineered MoO3 nanomaterials.