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arXiv · 1910.00142

Giant polarization charge density at lattice-matched GaN/ScN interfaces

Nicholas L. Adamski·Cyrus E. Dreyer·Chris G. Van de Walle
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Abstract

Rocksalt ScN is a semiconductor with a small lattice mismatch to wurtzite GaN. Within the modern theory of polarization, ScN has a nonvanishing formal polarization along the [111] direction. As a result, we demonstrate that an interface between (0001) GaN and (111) ScN exihibts a large polarization discontinuity of $-$1.358 $\rm Cm^{-2}$. Interfaces between ScN and wurtzite III-nitrides will exhibit a high-density electron gas on the (000$\bar{1}$) GaN interface or a hole gas on the (0001) GaN interface, with carrier concentrations up to $8.5 \times 10^{14}$ cm$^{-2}$. The large polarization difference and small strain makes ScN a desirable choice for polarization-enhanced tunnel junctions within the III-nitride materials system. The large sheet carrier densities may also be useful for contacts or current spreading layers.

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Nicholas L. Adamski, Cyrus E. Dreyer, Chris G. Van de Walle. 2019-12-19. Giant polarization charge density at lattice-matched GaN/ScN interfaces. https://doi.org/10.1063/1.5126717

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