ANNEALING TREATMENT OF THIN FILMS DEPOSITED BY SOL-GEL METHOD.

Highly transparent thin films were deposited on glass substrates by using a simple and inexpensive multi-step sol-gel spin coating process. This research investigated the effects of annealing temperature in the range from 350-600°C on the microstructure, surface morphology and optical properties of thin films by using XRD, SEM and transmittance spectra. The XRD results showed that the c-axis orientation of thin films was improved with the increase of annealing temperature. The grain size increases from 16.6-19.7 nm with the increase in temperature. The transmittance spectra indicated that the transmittance and direct optical band gap of the films showed a decreased trend with annealing temperature. It is found that the tensile stress exist in the films, which decreases with the increase in annealing temperature up to 500°C, on further increasing the annealing temperature up to 600°C, the stress in the film changes from tensile to compressive nature. [ABSTRACT FROM AUTHOR]