Morphology and growth mechanism of WOx films prepared by laser ablation of W in different atmospheres

摘要

Nanostructured tungsten oxide, WOx films were prepared by ablating a metallic target in helium, argon and dry air as buffer gases at fixed pressure, laser fluence and target-substrate distance. The obtained samples were observed by transmission and high-resolution electron microscopy. The morphologies and structures of the films are discussed and compared to the predictions of a model that interprets cluster growth in an expanding ablation plume as a function of process parameters.