Fabrication of YSZ solid electrolyte for solid oxide fuel cells by RF reactive sputtering

摘要

Yttria stabilized zirconia(YSZ) thin film electrolytefor solid oxide fuel cells(SOFCs) was reactively deposited by RFsputtering and its mechanical and electrical properties werecharacterized. Deposition rate of 8 mol% YSZ thin film was about100A/mm under the sputtering conditions of 14% of oxygen flowratio and 6.6 W/cm~2 of RF power density. Furthermore, surfaceroughness of YSZ thin films increased with increasing yttriacontent in the films and fine grain4ike particles were considerablyappeared, especially, in 8 mol% YSZ thin film. It was thought thatthese fine grain4ike particles were caused by un-resolved yttria andthat these were considerably reduced by post-annealing at 500 degC for 1 hr. The electrical conductivity of a triple layered 8 mol%YSZI3 mol% YSZI8 mol% YSZ thin film stack at 9000C wasslightly lower than that of a single layered 8 mol% YSZ thin filmwhich was most widely used solid electrolytes for SOFCs.However, the triple layered 8 mol% YSZ/3 mol% YSZI8 mol%YSZ thin film had lower compress stress and better microhardness than8 mol% YSZ thin films, exhibiting a possibility of application to SOFCs.