The effects of gadolinia-doped ceria (CGO, Ce0.8Gd0.2O1.9-x) and yttria-doped zirconia (8YSZ, Zr0.92Y0.08O2-x) interlayers prepared by spray pyrolysis between vacuum plasma-sprayed 8YSZ electrolytes (8YSZ-VPS) and screen-printed (La0.8Sr0.2)(0.98)MnO3 cathodes (LSM) on the power output of solid oxide fuel cells (SOFC) are investigated. Amorphous thin films are deposited and then converted to nanocrystalline electrolyte-cathode interlayers during the first heat-up cycle of a SOFC to the operating temperature. CGO thin films between the YSZ plasma-sprayed electrolyte and the LSM cathode increased the power output by more than 20% compared to cells without interlayers, whereas YSZ films degraded the power output of cells. It is assumed that CGO improves the charge transfer at the electrolyte-cathode interface and that the CGO layer prevents the formation of undesirable insulation of La-zirconate at the interface 8YSZ/LSM. (c) 2006 Elsevier B.V. All rights reserved.