Bi5GexSe95
x (30, 35, 40 and 45 at.%) thin films of thickness 200 nm were prepared on glass substrates by
the thermal evaporation technique. The influence of composition and annealing temperature, on the
structural and electrical properties of Bi5GexSe95
x films was investigated systematically using X-ray
diffraction (XRD), energy dispersive X-ray analysis (EDX). The XRD patterns showed that the as-prepared
films were amorphous in nature with few tiny crystalline peaks of relatively low intensity for 30 and
45 at.% and the Bi5Ge40Se55 annealed film was polycrystalline. The chemical composition of the Bi5Ge30Se65
film has been checked using energy dispersive X-ray spectroscopy (EDX). The electrical
conductivity was measured in the temperature range 300e430 K for the studied compositions. The effect
of composition on the activation energy (DE) and the density of localized states at the Fermi level N(EF)
were studied, moreover the electrical conductivity was found to increase with increasing the annealing
temperature and the activation energy was found to decrease with increasing the annealing temperature.
The results were discussed on the basis of amorphous-crystalline transformations.