Atomic Layer Deposition of Zirconium Oxide for Fuel Cell Applications

Solid oxide fuel cells (SOFCs) are an intriguing renewable energy source. Most SOFCs operate at high temperatures, around 1000 °C. One of the problems with them operating at lower temperatures is that it increases the resistance in the electrolyte layer. The focus of this project is to increase the efficiency of the electrolyte layer at the lower temperatures by decreasing the thickness of the electrolyte layer, in order to decrease the ionic resistance. Atomic layer deposition (ALD) was used to deposit zirconium oxide, which is one of the promising components of electrolytes in small length scale fuel cells; the zirconium precursor was Tris(dimethylamino)cyclopentadienylZirconium (ZyALD) and the oxidant was 0.1 % O3 in O2. Spectroscopic ellipsometry was used to measure the thickness of the samples was. This paper also describes how ALD was used to vary the thickness from 32 Å to 135 Å. Our results showed that there was a constant growth rate of 0.87 ± 0.04 Å/cycle, which can be used to control the film thickness. The error was calculated by taking the standard deviation of the growth rates for a varied number of cycles that were run.