Thermal annealing induced physical properties of electron beam vacuum evaporated CdZnTe thin films.

The thermal annealing induced physical properties of electron beam vacuum evaporated CdZnTe thin films have been investigated in the present work. The films of thickness 300 nm were deposited on indium tin oxide coated glass substrates followed by thermal annealing at 100 °C, 200 °C and 300 °C. The pristine and annealed films were subjected to the X-ray diffraction, UV–Vis spectrophotometer, Fourier transform infrared (FTIR) spectroscopy, source meter and Energy-dispersive spectroscopy for structural, optical, electrical and elemental composition analysis respectively. The structural analysis revealed that the films have cubic oriented polycrystalline structure with preferred orientation (111). The optical absorbance is found to increase with annealing while optical energy band gap is observed to decrease. Different optical constants like absorption coefficient, refractive index, dielectric constants and energy loss functions have been calculated using Herve-Vandamme model, dielectric theory, Swanepoel model and discussed. The FTIR study indicates the absorption intensity is increased with annealing temperature. The elemental analysis revealed to the presence of Cd, Zn and Te elements in the deposited films. The current-voltage tests show that the electrical conductivity is increased with thermal annealing. The results revealed to a demanding behavior of annealed films for the solar cell applications. [ABSTRACT FROM AUTHOR]