Optical and electrical transport properties of spray deposited CdS1−xSex thin films

CdS1−xSex thin films with different compositions have been deposited on amorphous glass substrates by spray pyrolysis technique. The spectrum shows a sharp fall in absorbance at wavelength corresponding to the band gap of the material. The optical band gap has been determined for all compositions and found to be direct allowed. The band gap has been observed to strongly depend on the film composition. The electrical conductivity of the deposited films has been studied as a function of temperature. All the films showed a transition from phonon-assisted hopping conduction through the impurity band to grain boundary limited conduction in the conduction/valence band at temperature around 370 K. The conductivity is found to vary with composition. The activation energies of the films of different compositions determined at low and high-temperature region have been observed to be in the range 0.113–0.323 eV. The Hall effect studies carried out on the deposited thin films reveal that films exhibit n-type of conductivity. The carrier concentration has been determined from Hall effect studies and is of the order of 1015 cm−3.