Interface polarization model for a 2-dimensional electron gas at the BaSnO(3)/LaInO(3) interface

In order to explain the experimental sheet carrier density n(2D) at the interface of BaSnO(3)/LaInO(3), we consider a model that is based on the presence of interface polarization in LaInO(3) which extends over 2 pseudocubic unit cells from the interface and eventually disappears in the next 2 unit cells. Considering such interface polarization in calculations based on 1D Poisson-Schrödinger equations, we consistently explain the dependence of the sheet carrier density of BaSnO(3)/LaInO(3) heterinterfaces on the thickness of the LaInO(3) layer and the La doping of the BaSnO(3) layer. Our model is supported by a quantitative analysis of atomic position obtained from high resolution transmission electron microscopy which evidences suppression of the octahedral tilt and a vertical lattice expansion in LaInO(3) over 2–3 pseudocubic unit cells at the coherently strained interface.