Gadolinia Doped Ceria Thin Films Prepared by Aerosol Assisted Chemical Vapor Deposition and Applications in Intermediate-Temperature Solid Oxide Fuel Cell

Abstract

Gadolinia doped ceria thin films are prepared from tetra-methylheptanedionate precursors by aerosol assisted chemical vapor deposition, an up-scalable non-vacuum thin film deposition technique. Film growth is studied at substrate temperatures between 300 abnd 633 degrees C, and microstructure, cation composition and cross-plane conductivity are assessed. While the total conductivities of gadolinia doped ceria layers deposited at 450 degrees C are slightly lower than the ionic grain conductivity of Ce0.8Gd0.2O2-delta, they are comparable to total conductivities reported for microcrystalline samples in literature. Furthermore, deposition at such low temperatures is promising for processing of thin film assemblies. The preparation of bi-layer electrolytes of yttria stabilized zirconia and gadolinia doped ceria thin films by aerosol assisted chemical vapor deposition is demonstrated. Gadolinia doped ceria films as thin as 150?nm are applied as barrier layers between yttria stabilized zirconia electrolyte and La0.6Sr0.4CoO3 delta cathode in anode supported solid oxide fuel cells. High power densities above 850 mW cm(2) at 650 degrees C are only obtained with these barrier layers, indicating that the GDC thin films effectively inhibit the formation of unwanted interface reactions.