Electrospray and pressurized spray deposition of yttria-stabilized zirconia films

Yttria-stabilized zirconia (YSZ) films (<1 μm thickness) were deposited on hot substrates by electrostatic and pressurized atomization. Droplet transport and evaporation are examined with a Phase Doppler Anemometer while the film morphology and composition are investigated by Scanning Electron Microscopy and Energy Dispersive X-ray Analysis. The effects of spraying configuration, solvent/precursor composition and substrate temperature on the resulting film morphology are examined. Smooth and dense YSZ films can be made at substrate temperatures above the solvent boiling point while precursor influence is negligible. Furthermore, the spray droplet has to reach the substrate without solid precipitation in the droplet or complete evaporation of the solvent. A deposition diagram for film texture was developed as function of droplet size, precursor concentration and substrate temperature using a theoretical model for electrospray droplet transport and evaporation.