Oral Polar catastrophe by fractional charge differences

Abstract

Ab-initio calculations within density functional theory are used to investigate the electronic states at the stoichiometric SnO/SnO2(110) interface. Although the interface lacks a polar discontinuity, we observe the formation of a two dimensionalhole gas between wide band gap semiconductors. We explain the findings by providing a model based on the idea that thestoichiometry discontinuity between SnO and SnO2 creates fractional charge differences, which in turn drive a polar catastrophescenario.