Electrical properties of thin yttria-stabilized zirconia overlayers produced by atomic layer deposition for solid oxide fuel cell applications

Thin films of yttria-stabilized zirconia (YSZ) electrolyte were prepared by atomic layer deposition at 300 °C for solid oxide fuel cell (SOFC) applications. YSZ samples of 300-1000 nm thickness were deposited onto La_0.8Sr_0.2MnO₃ (LSM) cathodes. A microstructural study was performed on these samples and their electrical properties were characterised between 100 and 390 °C by impedance spectroscopy. A remarkable feature is that the as-deposited layers were already crystalline without any annealing treatment. Their resistance decreased when reducing the layer thickness; nevertheless, their conductivity and activation energy were significantly lower than those reported in the literature for bulk YSZ.