Synthesis of vanadium pentoxide (V2O5) nanobelts with high coverage using plasma assisted PVD approach

Cost-saving, easy-handling, and eco-affable plasma assisted sublimation process (PASP) is proposed to synthesize vanadium pentoxide (V2O5) nanobelts (NBs) with excellent coverage on Si [1 0 0] wafer using oxygen plasma without using surfactants/catalysts. Pure orthorhombic V2O5 NBs having average length of few hundred of microns with quite uniform width nearly of 100 nm are formed at 500 degrees C. No film is deposited on Si in presence of oxygen gas without exciting plasma at 500 degrees C. HRTEM analysis with SAED pattern confirm that all V2O5 NBs are single crystalline in nature with the fringe width of 0.33 nm corresponding to [0 1 0] crystal plane. The XPS analysis shows the compositional purity and sub-stoichiometric nature of V2O5 NBs. The sub-stoichiometric nature of NBs is manifested through an appearance of low intensity peak corresponding to low oxidation state of V (i.e. V4(+)) at the binding energy of 514.8 eV. The micro-Raman and FTIR analysis of NBs are carried out to study the different vibrational modes exhibited by V and O atoms coordinated in distinct fashions. The nanobelts exhibit room temperature PL emission in UV-visible realm with a broad hump in the range of 450-750 nm, which confirms the presence of oxygen defects in NBs and strongly supports the XPS results as well. The possible growth mechanism of alpha-V2O5 NBs is proposed in this paper briefly. (C) 2015 Elsevier B.V. All rights reserved.