Fig. 5From: Surface Proton Conduction of Sm-Doped CeO2-δ Thin Film Preferentially Grown on Al2O3 (0001)PES spectra of the O 1s core level of dry- and wet-annealed thin films. The blue, green, and yellow curves are the O2− in the lattice site, and OH− and H2O on the surface, respectively, obtained from Gaussian fittingBack to article page