Influence of sintering temperature on structural, morphological and optical properties of nanocrystalline bismuth ferrite thin films via sol-gel processing

Abstract

Abstract Nanocrystalline thin films of pure bismuth ferrite were synthesized by sol-gel deposition technique on the corning glass substrate. The influence of sintering temperature on microstructure, morphology, and optical parameters has been systematicallystudied. Optimization of sintering temperature for single-phase nanocrystalline bismuth ferrite fabrication was carried out and found to be at 550 °C. X-ray diffraction confirms the presenceof distortedrhombohedral perovskite structure of bismuth ferrite oriented along (hkl) plane of (101).Surface morphology and Root mean square (RMS) surface roughness of the thin films prepared were determined from the micrographs of atomic force microscopy (AFM).Several optical constants viz. bandgap energy, extinction coefficient,Urbach energy, has been determined using Ultraviolet-Visible spectroscopy of the thin films within the range 200 -800 nm. With the increase in sintering temperature, there is a decrease in the optical bandgap of the material which would be essential for the wide range of applications in thin-film solar cells along with optoelectronic devices.