Structural and Surface Morphology of Multi-phase Cadmium Stannic Oxide Thin Films Prepared by Spray Pyrolysis Technique

Abstract

In this study, cadmium stannic oxide (Cd-Sn-O) (CSO) thin films of different Sn mole fractions (Sn/(Sn+Cd)) were prepared by spray pyrolysis. X-ray diffraction measurements showed polycrystalline structures of Cd₂SnO₄ phase and minor phases of CdSnO₃ and SnO₂ at 0.1 Sn ratio. Increasing the Sn concentration caused reducing the polycrystalline structure phase of Cd₂SnO₄ and increasing CdSnO₃ being the dominant phase at 0.3 Sn mole fraction. The polycrystalline structure phase of SnO₂ appeared as dominant at 0.5 Sn mole fraction. Field Emission Scanning Electron Microscopy (FE-SEM) was employed to investigate CSO that was prepared at different Sn mole fractions. The FE-SEM results of CSO thin films at 0.1 mole fraction showed nanorods which are 266 nm in diameter and the dimensions of the observed nanorods showed maximum at 0.2 Sn mole fraction. The sample prepared with 0.3 Sn mole fraction appeared as two particle structures; small spherical structures with a diameter of 250 nm attached to each other covered by radially branched laminate structures on the film surface. These shapes were about 470 nm wide and 3.5 μm long. In the sample type, at 0.4 Sn mole fraction, the lamellar structure emerged to curl and covered a larger area of ​​the film surface. At the ratio of 0.5, the lamellar structure covered the entire surface of the film.