Formation of composite coatings by ion-beam spraying of targets based on pyrogenic silica micro-powders containing copper compounds

Abstract

In the introduction, the object of research is indicated – thin films obtained by ion-beam spraying of targets based on pyrogenic silica micro-powders containing copper compounds. The aim of the research is to study the behavior of copper ions during the formation of thin films by ion beam sputtering of a SiO2:CuO target in an Ar/O2 mixture of gases. The main part presents the results of a study of the structural and optical properties of thin films (~ 100 nm thick) formed by ion beam spraying of targets based on pyrogenic silica micro-powders containing copper compounds. The morphology of the film surface as a whole shows integral homogeneity and in fact does not depend on the composition of the gas medium, while there is some ‘‘granularity’’ of the coating surface, which is typical for spraying porous targets consisting of agglomerates or domain structures. The obtained frequency dependences of the dielectric constant of SiO2:CuO films showed a decrease in the dielectric constant in the range of 10 kHz – 1 MHz. It was found that when the SiO2:CuO film thickness is less than 100 nm, a thin-film capacitor is not always formed. Based on the analysis of the optical parameters of film accumulation depending on the sputtering medium, it was suggested that in an inert medium a large absorption of globular spheroidal CuO is formed in the film, and copper oxide can also be reduced to Cu+ and possibly to Cuº. It is indicated by the change in ε and tgδ, as well as an increase in the optical prohibited gap of SiO2:CuO thin films from 3.91 to 3.97 eV with an increase in the oxygen content in the Ar/O2 gas mixture. The resulting films can be used as active media in solar cells, sensors and other devices.