Band gap energies of CdO : F semiconductor films produced by ultrasonic spray pyrolysis method

Abstract

The fluorine doped cadmium oxide (CdO:F) samples have been deposited by ultrasonic spray pyrolysis method (USP). The absorption spectra of the samples showed that CdO:F is a direct band gap material. The direct optical transition has shifted towards the shorter wavelengths, and the transparency of the material has increased at a given wavelength above the fundamental absorption edge. The optical band gap (E-g) has found to be 2,28 eV for undoped CdO films. A shift in the absorption edge of the fluorine doped CdO films with increasing fluorine concentration is explained by means of the Moss-Burstein effect.