Influence of γ-irradiation on the optical properties of AgSbSe2 thin films

• Effect of γ-dose on the optical properties of AgSbSe2 films was investigated.
• The refractive index increase whiles the optical band gap decrease with γ-dose.
• The refractive index is adequately described by single oscillator model.
• The variation of the optical band gap and the Urbach‘s energy have been explained.

Amorphous AgSbSe2 thin films were deposited onto glass substrates using electron beam evaporation. The effect of γ-irradiation on the optical properties of the deposited AgSbSe2 films was studied in the wavelength range 550–2500 nm. A red shift in the transmission spectra was observed with increasing γ-irradiation dose. The refractive index of the deposited films was determined as a function of γ-dose. It was established that exposure of the deposited films to γ-radiation leads to increased refractive index in the whole spectral region. The refractive index dispersion of the deposited films is adequately described by the single oscillator model, whereby, the values of the oscillator parameters were determined as a function of γ-dose. Analysis of the optical absorption coefficient revealed the presence of an indirect optical transition with band gap value decreases with increasing γ-dose.