Scientists are drawn much attention towards transition metal oxides due to their interesting physics and engineering applications. As a result of their different oxidation states, they exhibit promising structural, electrical, magnetic, and optical properties, as well as high melting points[1–2]. Molybdenum trioxide (MoO3) is one of the transition metal oxides, which attracted scientific community owing to its attracting properties such as tunable band gap, various stable oxidation states [3]. In additions, molybdenum oxide (MoO3) exhibits interesting structural, chemical, electrical, and optical properties that make it an ideal metal oxide for use in chemical, optical, and electronic applications [4].
Due to the various exceptional properties MoO3 finds potential applications in diverse fields such as batteries, smart window, optical switches, catalysis, solar cells, gas sensors, and energy storage [5–8]. MoO3 thin films exist in three phases, namely: (i) orthorhombic α-phase, (ii) monoclinic β-phase, and (iii) hexagonal h-phase [9]. The α-MoO3 phase is formed by two bi-layers parallel to the (010) plane. The edge forms the α-phase of MoO3 and corner-sharing MoO6 octahedral linked to create bilayer sheets that are stacked in the (010) direction. Additionally, MoO3 has versatile morphological structures, including nanobelts, nanorods, nanowires, etc., offering a high surface-to-volume ratio [10–12]. Gases such as nitrous oxide, nitrogen dioxide, carbon monoxide, and ammonia are extremely sensitive to MoO3 thin films at temperatures between 573 and 873 K [13]. Because of their morphology, MoO3 nanobelts have a high rate capacity, so they are used in hybrid electric vehicles as cathode materials for rechargeable lithium batteries. Molybdenum oxide has the highest oxygen concentration and acts as a doping center that controls the material's electrical and optical properties [14].
The MoO3 thin films have been deposited using different deposition techniques such as sputtering [15], thermal evaporation [16], atomic layer deposition [17], spray pyrolysis [18], hydrothermal method [19], sol-gel spin coating [20] etc. Nirupamaetal et al [21] reported the formation of nanostructured -MoO3 thin films by magnetron sputtering was reported in [22]. Bouzidietal. [23] analysed the effects of substrate temperature on the structural and optical properties of MoO3 thin films.
In the present research work spray pyrolysis technique were used for the deposition of MoO3 thin films on glass substrate for different substrate temperature. The effect of deposition temperature on structural and morphological properties of MoO3 thin films was investigated.