Optical properties of CdxZn(1−x)O films deposited by ultrasonic spray pyrolysis method

Cd_xZn_(1−x)O (x = 0, 0.59, 0.78 and 1) films have been produced by ultrasonic spray pyrolysis technique using aqueous solutions of CdCl₂ H₂O and ZnCl₂ on the microscope glass substrate between 325 and 400 °C. The Cd_xZn_(1−x)O samples have been crystallized both cubic and hexagonal structures. The optical properties of the samples were characterized by transmittance and absorption spectroscopy measurements. Transmissions of the samples have decreased with increasing x values. The optical band gap energies of the Cd_xZn_(1−x)O samples from the absorption spectra have been calculated between 2.48 and 3.23 eV by different Zn contents. The samples were annealed at 350 and 450 °C. The optical band gap energy has decreased at 350 °C whereas it increased at 450 °C.