Morphological and optical evolution of different organic acids used MoO3 thin films by spin coating method.

Molybdenum trioxide (MoO 3 ) thin films were prepared at room temperature (RT) and at different annealing temperatures of 250, 350, 450 and 550 °C. We also prepared MoO 3 films using additives of water-soluble and water-insoluble organic acids. The thin films were coated using the spin coating technique and annealed at 350 °C temperature. The effects of different annealing temperatures and different organic acid additives on MoO 3 films were characterized by structural and optical studies. From the XRD pattern, the structure of the MoO 3 films is found to vary with respect to increase in the annealing temperature. For RT and 250 °C, the hexagonal structure was observed and for 350, 450 and 550 °C, the orthorhombic structure was observed. The XRD pattern for all the organic acid additive used MoO 3 films exposed the orthorhombic structure. SEM images show hasty variations in the surface morphology for different annealed MoO 3 films and different additive used MoO 3 films. The EDX analysis confirmed the presence of Mo and O elements for all the films. The UV–vis results show the absorbance and transmittance values. The band gap energy was found to be around 3.8 eV for all the MoO 3 films. [ABSTRACT FROM AUTHOR]