Effects of substrate temperature on the properties of CdSnSe thin films deposited by nebulizer spray pyrolysis technique

Abstract

Thin films of cadmium tin selenide (CdSnSe) have been prepared on glass substrates at different temperatures by the nebulizer spray pyrolysis (NSP) technique using aqueous solutions of cadmium chloride (CdCl2), tin chloride (SnCl2) and sodium selenosulphate (Na2SeSO3). The deposited films were characterized by structural, morphological, compositional, optical and electrical properties. X-ray diffraction studies confirm that the CdSnSe films are polycrystalline in nature having mixed phase (hexagonal+cubic) crystal structure with preferential orientation (102) plane which corresponds to hexagonal crystal structure. Scanning electron microscopy studies reveal that the prepared films are having smooth and uniform surface with dense surface morphology well-covered over the entire substrate surface without any cracks. The UV–vis spectroscopy confirms the formation of good transparent CdSnSe films with an average transmission ∼60% in the visible region. Optical band gap energies of the films are found to be varied from 1.6–1.625eV depending on the substrate temperatures. The temperature dependence of the electrical conductivity during the heat treatment was also studied. The electrical conductivity of the films is found to be in the order of 10−3Ω-cm−1 and increases with temperature.