ZrO2–In2O3 thin layers with gradual ionic to electronic composition synthesized by atomic layer deposition for SOFC applications

To achieve the processing of high performance solid oxide fuel cells (SOFCs) operating in the intermediate-temperature range (600-750 degrees C), either a thin layer electrolyte configuration or development of a new electrolyte material with high ionic conductivity is needed. In this work, atomic layer deposition, ALD, was used to process at 300 degrees C ZrO2-In2O3 thin layers which can be mixed ionic and/or electronic conductors depending on the amount of indium oxide. Single thin layers with different compositions and a thin multilayer with a composition gradient were deposited. The structural and morphological properties were analyzed by SEM/EDX and XRD. The deposits were well-crystallized without post-deposition annealing. Impedance spectroscopy measurements showed that the ZrO2-In2O3 gradient of composition seems to improve the interface properties.