Investigation of dispersion parameters, dielectric properties and opto–electrical parameters of ZnO thin film grown by ALD

Abstract

Highly transparent zinc oxide thin films with varied layer thicknesses have been prepared on microscopic glass substrates at 200 °C. Films thickness was measured by stylus profilometer. The films have been investigated for their structure using X-Ray diffraction; the patterns showed their amorphous nature. The dispersion parameters i.e. refractive index (n) and extinction coefficient (k) are computed in the wavelength range (350–2500 nm). The Tauc model was used to determine the optical band gap and Urbach tail with direct allowed transitions. The real and imaginary parts of the high frequency dielectric constant were discussed. Other parameters such as penetration depth, cut-off wavelength, dissipation factor, volume and surface energy loss functions, reflection loss factor, optical, electrical and thermal conductivities have also been determined. A systematic study of a wide range of optical parameters of ALD prepared ZnO films can serve as a valuable data source and can enrich the knowledge of the studied material.