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arXiv · 1812.07188

First principles study of hBN-AlN short-period superlattice heterostructures

Catalin D. Spataru·Mary H. Crawford·Andrew A. Allerman
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Abstract

We report a theoretical study of the structural, electronic and optical properties of hBN-AlN superlattice heterostructures (SL) using a first-principles approach based on standard and hybrid Density Functional Theory. We consider short-period ($L<10$ nm) SL and find that their properties depend strongly on the AlN layer thickness $L_{AlN}$. For $L_{AlN}\lesssim1$ nm, AlN stabilizes into the hexagonal phase and SL display insulating behavior with type II interface band alignment and optical gaps as small as $5.2$ eV. The wurtzite phase forms for thicker AlN layers. In these cases built-in electric fields lead to formation of polarization compensating charges as well as two-dimensional conductive behavior for electronic transport along interfaces. We also find defect-like states localized at interfaces which are optically active in the visible range.

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Catalin D. Spataru, Mary H. Crawford, Andrew A. Allerman. 2018-12-18. First principles study of hBN-AlN short-period superlattice heterostructures. https://doi.org/10.1063/1.5052140

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