ALUMINUM DOPING EFFECT ON THE STRUCTURAL AND OPTICAL PROPERTIES OF NANOCRYSTALLINE SNO2 THIN FILMS FOR SOLAR CELLS APPLICATIONS

Abstract

Pure tin dioxide (SnO2) films doped with aluminum for different volume ratios (1%, 3%, 5%) were prepared using Chemical Spray Pyrolysis Technique (CSPT). The results of X-ray diffraction (XRD) showed that the prepared films (pure SnO2 and SnO2:Al) are polycrystalline with a tetragonal structure, and that the intensity as well as the grain size is decreasing with increasing Al doping.Scanning Electron Microscope results showed thatthe the films are homogeneous which have semi-spherical grainswith uniform distribution on the surface. The results of atomic force microscopy (AFM) showed that the films have nanocrystallinestructure,small roughness, no cracks and the average of particle size decreases with the increasealuminum doping.The results of the optical properties in the range of wavelengths (300-1100 nm), showed that the transmittance and energy gap decrease when doping with aluminum.