Optical and Electrical Properties of the Ge10 Inx Se(90-x) Amorphous Thin Film

Thin films of Ge10InxSe90-x (x = 5, 10, and 15%) were prepared by the conventional thermal evaporation technique. X-ray diffraction measurements have shown that Ge10InxSe90-x (x = 5, 10, and 15%) thin film form has an amorphous nature. The optical and electrical properties of Ge10InxSe90-x (where x=5, 10, 15%) were studied. Transmittance and reflectance measurements were used to calculate the optical energy gap, band tail width of the localized states and the optical constants [refractive index (n), absorption index (K) and absorption coefficient (α), real and imaginary parts of dielectric constant (ε’,ε’’) respectively].
The optical bands were found to decrease with increasing In content, while the width of the tails of the localized state increases. The results of the electrical conductivity measurements showed that the conductivity increased and activation energy of conduction decrease with increasing In content. The obtained results show that the activation energy was less than optical band gap for the investigated samples.