Electrical conductivity, optical absorption and structural studies in thin films

Abstract

Electrical, optical and structural properties of thin films deposited on glass substrates are studied for different substrate and post-deposition annealing temperatures. The substrate temperature is varied in the range 300 - 773 K. The activation energy has been calculated for the films using the Arrhenius plot and the bandgap has been obtained from the optical transmission spectra. The activation energy varied from 76 meV to 330 meV for in the impurity scattering region and for the value is around 700 meV in the intrinsic region. Optical absorption spectra show variation in the bandgap, varying from 1.18 to 1.42 eV as the substrate temperature varied from 300 - 773 K. Films deposited at higher substrate temperatures give a = 5.93 Å and c = 11.22 Å for the tetragonal phase. The mean grain size of the films is for polycrystalline films.