The effect of γ-irradiation on the optical parameters of AgInTe₂ Films

Abstract

Some optical properties in AgInTe₂ thin films are studied as a function of γ dose. The absorbance and transmittance spectra of the films were analyzed. The compound shows an allowed direct transition near the fundamental absorption edge E _g1, in addition to a transition originating from the crystal field split level E _g2. The direct energy gap E _g1 increases from 1.16eV for un-irradiated to 1.24eV for higher dose (2.5 Mrad) irradiated films. The increase of E _g1 was attributed to the increase of the crystallinity. Urbach's relation was used to calculate the values of the band tails E _e in the fundamental edge which decrease from 2.66 to 1.26eV as γ dose increases. E _g2 exhibits opposite trends, which indicate that most of the transitions, can occur from the splitting levels according to a suggested model.

Key Words:

• Evaporation
• Thin films
• Optical properties
• Radiation