Structural, optical and electrical properties of Zr-doped In₂O₃ thin films

Undoped and zirconium doped indium oxide (ZrIO) thin films were deposited on glass substrate at a substrate temperature of 450°C by spray pyrolysis method. The effect of zirconium (Zr) dopant concentration (0-11 at.%) on the structural, morphological, optical and electrical properties of n-type ZrIO films were studied. X-ray diffraction (XRD) results confirmed the polycrystalline nature of the ZrIO thin film with cubic structure. The grain size was decreased from 25 to 15.75 nm with Zr doping. The scanning electron microscopy (SEM) showed that the surface morphology of the films were changed with Zr doping. The surface roughness of the films was investigated by atomic force microscopy (AFM) and was found to be increased with the increasing of Zr doping percentage. A blue shift of the optical band gap was observed. The optical band was gap decreased from 3.50 to 3.0eV with increase in Zr concentrations. Room temperature photoluminescence (PL) measurement of the deposited films indicated the incorporation of Zr in In2O3 lattice. The film had low resistivity of 6.4 × 10(-4)Ωcm and higher carrier concentration of 2.5 × 10(20) was obtained at a doping ratio of 7 at.%.