Vibrational and morphological properties of Sn-doped CdS films deposited by ultrasonic spray pyrolysis method

Cd 1− x Sn x S films ( x=0.0, 0.1 and 0.2) were prepared by the ultrasonic spray pyrolysis (USP) method on the glass substrate at 300 °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 Cd 1− x Sn x S were recorded. The Raman spectrum for Cd 1− x Sn x 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 −1. The absorption peaks in the FT-IR spectra of Cd 1− x Sn x 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.