Cd1-chi Sn chi S films (chi=0.0, 0.1 and 0.2) were prepared by the ultrasonic spray pyrolysis (USP) method on the glass substrate at 300 degrees C. Effect of Sn doping on the vibrational and morphological properties of CdS films has been investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM), FT-IR and Raman spectroscopy. The SEM and AFM measurements showed that the surface morphology of the films was affected by the tin incorporation. The Raman (200-700 cm(-1)) and FT-IR (400-4000 cm(-1)) spectra of Cd1-chi Sn chi S were recorded. The Raman spectrum for Cd1-chi Sn chi S films is dominated by an intense band at 300 cm(-1), assigned to the first-order longitudinal optic phonon and the second-order phonon peak 599 cm . The absorption peaks in the FT-IR spectra of Cd1-chi Sn chi S located at 540-700 and 1004-1045 cm(-1) can be assigned to the Cd-S and C-O stretching frequencies, respectively. Raman and FT-IR spectra shows decrease in the peak intensity with increasing Sn concentration. (C) 2011 Elsevier Ltd. All rights reserved.