Pulsed laser-deposited SnOx: plasma expansion dynamics effects

Nanostructured thin films were deposited by excimer laser ablation of a hot pressed SnO2 target at the fixed laser fluence of 1.0 J cm-2 in a controlled oxygen atmosphere. Information about the film's structural properties has been obtained by means of micro-Raman and X-ray photoelectron spectroscopies. A different film morphology is observed by scanning and transmission electron microscope imaging. A smooth surface characterizes the sample grown at the lower pressure, while an irregular and rough surface is observed for pressures up to 13.3 Pa. Plasma expansion dynamics at different experimental conditions were studied by fast photography. Imaging of the laser-generated plasma allowed for the identification of plasma confinement, shock wave formation and plasma stopping. The structural properties of the deposited films are presented and discussed, considering the tin oxide plasma expansion dynamics and their influence on the nanostructured growth mechanisms.