Abstract
XPS core level and valence band spectra are presented for a chemically etched epitaxial thin film of superconducting HgBa2CaCu2O6+δ (Tc = 123 K) on a SrTiO3 (100) substrate. These data exhibit lower levels of high binding energy contaminant signals in the O 1s and alkaline earth core level regions compared to studies in the literature, and a clear Fermi edge in the valence band region, evidence of a high quality surface.