Properties Of Nanosized Zno:Ho Films Deposited Using Explosive Evaporation

The properties of nanosized ZnO:Ho thin films deposited by explosive evaporation method have been studied. This work is aimed at studying the effect of high deposition rate on the oxide characteristics interesting from the viewpoint of photocatalysis, namely: morphology and structure, electrical and optical properties, lifetime of charge carriers. Explosive deposition of films defines the novelty of this work as compared to majority of previous studies devoted to nanosized ZnO:Ho photocatalysts, which used equilibrium methods for their synthesis. Methods of scanning electron microscopy, XRD analysis, photoluminescence, and Raman scattering have shown that in ZnO:Ho films deposited using explosive evaporation, with increasing holmium content, amorphization of their structure and morphology are observed. It is related with random incorporation of holmium atoms into the crystalline lattice of ZnO as well as with the fact that the ionic radius of Ho3+ exceeds that of Zn-2(+). It is accompanied by a shift of the edge of ZnO absorption toward the long-wave (blue) spectral range, the decrease of the bandgap as well as an increase in the resistivity and lifetime of charge carriers. All these changes are favourable for the photocatalytic process involving nanostructures based on ZnO:Ho.