Studies on microstructure and optoelectronic properties of metal oxide nanostructured coatings

Abstract

The chosen research problem is all about preparation and property newlineanalysis of metal oxide thin films. Among the available metal oxides, newlinechromium (III) oxide has been identified as a unique, dense, newlinethermodynamically stable at temperatures beyond 500 °C. It is the hardest newlinetransition metal oxide. In the present study, chromium oxide (Cr2O3) thin films newlinehave been prepared using the spray pyrolysis method. Metal ion doping is a newlinepromising method that influences the features of the material by intentionally newlineadding impurities or defects into the lattice. Hence, with the pure chromium newlineoxide thin films, transition metal ion (Mg, Fe, and Sn) doped Cr2O3 film newlinesamples were prepared in the spray pyrolysis method for varied dopant newlineconcentrations (2, 4, 6 and 8 wt. %). All the employed studies revealed good newlineresults and hence the formulated thesis is in full satisfaction that is provocative newlinein all respects. newlineAs various polymorphs are available for chromium oxide, thin layered newlinecoatings of hexagonal Cr2O3 have been deposited using spray pyrolyzed newlinechemical vapor deposition technique on glass substrates at 300 °C temperature. newlineUsing chromium nitrate precursor by varying the solution concentration, X-ray newlinediffraction outcomes showed that the deposited films were polycrystalline newlinenature and the vibrational characteristics were examined using Fourier newlinetransform infrared spectroscopic analysis. By increasing the chromium content, newlinethe transmission of light reduced and the optical study showed a direct type newlinetransition. Photoluminescence measurements were performed to investigate the newlinecarrier localization consequences and the evolution of peaks corresponding to newlineprecise wavelengths. The chemical compositions of the chromium oxide thin newlinefilm surface layer were computed by EDAX and XPS measurements. newlineMorphological observations indicated the compactness of grains and the newlineparticle structure varied significantly as the concentration increases. VSM newlinemeasurement denoted antiferromagnetic behavior at room temperature in favor newlineof chromium oxide films correspon