Comparison of optical properties of Cu- and In-doped CdO thin films having low dielectric loss

Abstract

Cu- (1%) and In- (1%) doped CdO thin films were produced using one-step electrochemical deposition method and their optical analyses were investigated with UV-vis spectrophotometer. The determined optical parameters were examined in depth and compared. It is obtained that the maximum absorption region of Cu- and In-doped CdO thin films were in ultraviolet region. The maximum absorption coefficient, energy band gap, average transmission, maximum extinction coefficient and refractive index values of Cu-doped thin film were found to be 1.8 x 10⁶ m^-1, 2.66 eV, 73.01%, 0.054 and 1.21, respectively, while these for In-doped CdO thin film were, 1.1 x 10⁶ m^-1, 2.48 eV, 72.45%, 0.078 and 1.17, respectively. Additionally, optical dielectric loss values of the Cu- and In-doped thin films were determined, and it was found that real dielectric constant values were considerably higher than imaginary dielectric constant values and dielectric loss values were quite low in both films. Optical conductivity of the Cu- and In-doped CdO thin films were also determined as 5.14 x 10¹⁴ and 5.14 x 10¹⁴, respectively.