Cluster size prediction in pulsed laser deposited films

摘要

Pulsed laser deposition in an inert ambient gas allows for producing cluster-assembled films whose constituent building blocks are atom aggregates with size ranging from a few to several thousands of atoms. The choice of the deposition parameters, such as gas pressure, laser energy density and target to substrate distance, affects cluster size and size distribution. By controlling these critical parameters the features of film surface can be managed at the scale of tens of nanometers, or less. We introduce a mixed propagation model, based on a modification of the diffusion and the drag models to calculate the size of clusters formed in the plume during its propagation. Model ingredients are quantities directly deduced from available values of process parameters. The mixed propagation model is applied to interpret experimental results on the synthesis of clusters of different elements.