Abstract
To investigate the effect of annealing on the structural and optical properties of a binary compound Ga5Se95, thin films of Ga5Se95 have been deposited on quartz substrates at room temperature by the thermal evaporation technique. X-ray diffraction patterns showed that the films before and after annealing at 573 K have polycrystalline texture and exhibit tetragonal structure. The dependences of the optical constants, the refractive index n and extinction coefficient k were studied in the spectral range of 200 nm to 2500 nm. The normal dispersion of the refractive index of the films could be described using the Wemple-DiDomenco single-oscillator model. Analysis of absorption index data reveals that as-deposited Ga5Se95 films has indirect transitions with optical energy gap of 1.685 eV. (C) 2011 Elsevier Ltd. All rights reserved.