An electronic and structural interpretation of tin oxide ELS spectra

In this study electron energy-loss spectroscopy (ELS) is used to examine polycrystalline tin oxide films which have been annealed, ion sputtered and oxygen treated. The major features in the N(E) loss spectrum are interpreted as due to collections of optically allowed interband transitions. It is demonstrated that depth profile information may be obtained by varying the primary electron beam energy. Combined ELS and valence-band XPS results indicate that a significant amount of structural information may be inferred from the size, shape and/or position of the N(E) ELS features. Core-level features are found to be quite sensitive to the presence of defects in an SnO₂ lattice with some specificity as to the type of defect.