Low-temperature growth of BaZrO3 and Ba(Zr,Y)O3−δ thin films via spray pyrolysis deposition

Abstract

BaZr1−xYxO3−δ (BZY) is a promising electrolyte for proton-conducting oxide fuel cells. However, the fabrication of BZY requires high-temperature processing (> ∼1700 °C) for densification, which makes the fabrication process expensive and may lead to degradation in fuel cell performance due to atomic diffusion at the electrode interface. To address these issues, this study focused on the deposition of BaZrO3 and BZY thin films via spray pyrolysis using an acetylacetonate-based precursor solution. Single-phase BaZrO3 thin films, featuring a columnar structure and preferential (100) orientation, were obtained at a substrate temperature of 800 °C in a 5 % O2 atmosphere. The BZY thin films could be obtained by incorporating Y into the precursor solution, and the composition of the thin films could be modulated by adjusting the precursor solution composition. No diffusion of Ni into the BaZrO3 thin film was observed when the BaZrO3 thin film was deposited on a NiO-BZY substrate at 800 °C. This suggests that the spray pyrolysis deposition of BZY thin films is an effective approach for fabricating a junction structure between the BZY electrolyte and electrode while avoiding atomic diffusion at the interface.