Surface electronic structure of rutile-type semiconductors: SnO 2(110) and TiO 2(110)

Abstract

We have investigated the electronic structure of the ideal (110) surfaces of the rutile structure compounds SnO 2 and TiO 2 using the scattering theoretic method. The results are presented in terms of surface bound states, surface resonances and wave vector resolved densities of states. For SnO 2(110), the dominant features are two backbond states in the stomach gap of the main valence band and two Sn-s derived states in the lower conduction band region. For TiO 2(110), we obtain no occupied surface states in the gap region, in agreement with UPS measurements on defectless TiO 2(110) surfaces. The creation of the surface leads essentially to O-p resonances in the valence band region and Ti-d resonances in the conduction band region.