Experimental and density-functional study of the electronic structure of In₄Sn₃O₁₂

The electronic structure of In4 Sn3 O12 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 O2p states with three distinct features emerging from the hybridization with In and Sn5s, 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.