US and CdS:Ni films (at the Ni percentages of 10 and 20) were deposited on glass substrates by ultrasonic spray pyrolysis (USP) technique at a substrate temperature of 300 +/- 5 degreesC. The effect of Ni incorporation on the film properties is presented. The variations of conductivities of US and CdS:Ni films were investigated depending on the temperature and applied voltage in dark and light conditions. The film structures were studied by X-ray diffraction (XRD). The crystallinity was spoiled with increasing Ni concentration, and a shift to amorphous structure was seen. Surface morphologies of the films were studied by scanning electron microscopy (SEM). The most homogeneous surface was seen in US films. Elemental analyses of all films were also studied by energy dispersive X-ray spectroscopy (EDS). (C) 2003 Elsevier Science B.V. All rights reserved.