High-performing gadolinium-doped ceria interlayer for thin film solid oxide fuel cell via sputtering process parameter control

Abstract

This study examines how sputtering deposition parameters — target-substrate distance (TSD) and chamber pressure — affect the microstructure, crystallinity, and performance of gadolinia-doped ceria (GDC) interlayers in thin-film solid oxide fuel cells (SOFCs). GDC interlayers are deposited under varying TSDs (13.3–18 .5 cm) and chamber pressures (10–50 mTorr). Microscopy images reveal that grain size decreases with increasing TSD up to 16.7 cm but increases at 18.5 cm due to gas-phase nucleation. Increasing chamber pressure from 10 mTorr to 30 mTorr reduces grain size; however, a further increase to 50 mTorr leads to larger grains due to gas-phase nucleation. An X-ray diffraction (XRD) analysis is carried out to reveal a crystal structure. Electrochemical testing indicates that the cell with an optimized GDC interlayer achieves the highest peak power density of 1.76 W/cm² at 500 °C — a 200 % improvement over the baseline. These results demonstrate that optimizing sputtering parameters can significantly enhance SOFC performance at lower operating temperatures.