Laser-Based Crystallization of Chemical Solution Deposited Proton-Conducting Thin Films

This work investigates the laser-based solid-phase crystallization of wet-chemically deposited BZY (yttrium doped barium zirconate) thin films on metallic substrates. For this purpose, amorphous BZY thin films are deposited on nickel-based alloy substrates using spin coating and are then annealed using laser radiation. Different laser intensities and scanning velocities are investigated. X-ray diffraction analysis of the processed thin films shows an initial increase in crystallinity with increasing laser intensity. A further increase in laser intensity leads to the formation of secondary phases and ultimately to the melting of the substrate material. Complete crystallization of the thin films without the formation of secondary phases is achieved by applying scanning velocities of vS ≥ 500 mm/s. Scanning electron microscopy images of selected samples show that, especially at higher scanning velocities, crack formation can occur as a result of the annealing. In summary, laser annealing is a promising approach for the thermal post-treatment of BZY thin films in applications in metal-supported solid oxide fuel cells.