Single oscillator energy and dispersion energy of uniform thin chalcogenide films from Cu-As-S-Se system

This paper presents some of the results obtained by using the modified envelope method, which takes substrate absorption into account. Samples investigated in this paper are the series of amorphous thin chalcogenide uniform films from system Cu-x[As-2(S0.5Se0.5)(3)](100-x). Thin films were deposited under vacuum on glass substrates by thermal evaporation technique, from previously synthesized bulk samples. The dispersion of the refractive index is discussed in terms of the single oscillator model proposed by Wemple and DiDomenico. By using this model, i.e. by plotting (n(2)-1)(-1) against (h omega))(2) and fitting a straight line, oscillator parameters, E-d - the single oscillator energy and E-d - the dispersion energy, were directly determined. (C) 2007 Elsevier B.V. All rights reserved.