The electronic structure of ${\text{In}}_4{\text{Sn}}_3{\text{O}}_{12}$ has been studied by optical and x-ray photoemission spectroscopies and has been compared to electronic structure calculations carried out using density-functional theory. An excellent agreement is found between the experimental valence-band structure and that predicted by the calculations. The valence band derives its dominant character from $\text{O}2p$ states with three distinct features emerging from the hybridization with In and $\text{Sn}5s$, $5p$, and $4d$ states, respectively. The position of the valence-band edge in the x-ray photoemission spectrum suggests a fundamental electronic gap of 2.7 eV whereas the onset of strong optical absorption is predicted to occur at 3.3 eV.

• Received 23 July 2009

DOI:https://doi.org/10.1103/PhysRevB.81.085110