Effect of disorder on the Raman scattering of CdSxSe1-x films deposited bylaser ablation

We present micro-Raman spectra at room temperature of CdSxSe1-x ternary fil ms deposited on Sill Ill-oriented substrates by means of the laser ablation technique, The lineshape of the LO phonon structure is characterized by si gnificant asymmetry and broadening induced by disorder in the alloy. The as ymmetric line profile can be described as a composite of two phonon modes, one ascribed to zone-center and the other to zone-edge phonons. Attempts to fit the experimental data to the spatial correlation model result in a poo r agreement. We discuss the possibility to include into the Lineshape analy sis the contribution from the disorder-activated phonon density of states. (C) 2000 Elsevier Science Ltd. All rights reserved.