The effects of substrate temperature and deposition time on structural and optical properties of 0.08M ZnO thin films

ZnO thin films were deposited by the ultrasonic spray pyrolysis technique onto microscope glass slides. The substrate temperature was varied from 350 degree C to 400 degree C in 25 degree C steps for the Set-1 and Set-2 samples having a 25 min and 50 min, respectively. The influence of substrate temperature and deposition time on structural and optical properties of 0.08M ZnO thin films was systematically investigated. The optical transmission spectra obtained over the 300-900 nm spectral range with a Cary-100 spectrophotometer were used to determine the optical constants of the ZnO films such as thickness, refractive index, and the optical band gaps. It is observed that while the film thickness decreases from 1455 nm to 870 nm for Set-1 and from 795 nm to 350 nm for the Set-2 samples with the substrate temperature, the refractive indices increases. However, the band gap values are about 3.2 eV.