An experimental investigation was made of the optical, electrical and microstructural properties of hetero-interfaces between the thin-film perovskite insulating materials, SrTiO3 and LaAlO3; deposited under various O pressure conditions. Cathode and photoluminescence experiments showed that O vacancies were formed in the bulk SrTiO3 substrate during the growth of LaAlO3 films, resulting in high electrical conductivity and mobility values. For both high and low O pressure interfaces, the electrical Hall mobilities obeyed a similar power-law dependence; as observed in O-reduced SrTiO3 bulk samples. The results were confirmed at a microscopic level, with local strain fields at the interface reaching 10nm into the SrTiO3 substrate.

Effect of Oxygen Vacancies in the SrTiO3 Substrate on the Electrical Properties of the LaAlO3/SrTiO3 Interface. A.Kalabukhov, R.Gunnarsson, J.Börjesson, E.Olsson, T.Claeson, D.Winkler: Physical Review B, 2007, 75[12], 121404 (4pp)