Interface polarization model for a 2-dimensional electron gas at the BaSnO3/LaInO3 interface

Young Mo Kim; T Markurt; Youjung Kim; M Zupancic; Juyeon Shin; M Albrecht; Kookrin Char

doi:10.1038/s41598-019-52772-8

Interface polarization model for a 2-dimensional electron gas at the BaSnO₃/LaInO₃ interface

Sci Rep. 2019 Nov 7;9(1):16202. doi: 10.1038/s41598-019-52772-8.

Authors

Young Mo Kim¹, T Markurt², Youjung Kim¹, M Zupancic², Juyeon Shin¹, M Albrecht², Kookrin Char³

Affiliations

¹ Institute of Applied Physics, Dept. of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea.
² Leibniz-Institut für Kristallzüchtung, Berlin, 12489, Germany.
³ Institute of Applied Physics, Dept. of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea. kchar@phya.snu.ac.kr.

Abstract

In order to explain the experimental sheet carrier density n_2D at the interface of BaSnO₃/LaInO₃, we consider a model that is based on the presence of interface polarization in LaInO₃ 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 BaSnO₃/LaInO₃ heterinterfaces on the thickness of the LaInO₃ layer and the La doping of the BaSnO₃ 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 LaInO₃ over 2-3 pseudocubic unit cells at the coherently strained interface.

Abstract

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