Nanoscale Effects on Heterojunction Electron Gases in GaN/AlGaN Core/Shell Nanowires

TL;DR

This paper theoretically investigates how nanoscale effects influence the formation and properties of heterojunction electron gases in GaN/AlGaN core/shell nanowires with different cross-sectional geometries, revealing unique electron behaviors at the nanoscale.

Contribution

It provides a detailed theoretical analysis of electron gases in GaN/AlGaN nanowires, highlighting geometry-dependent effects and differences from bulk materials.

Findings

Degenerate quasi-one-dimensional electron gases at hexagon corners

Transition to core-centered electron gases at lower doping

Distinct electron gas behaviors in polar triangular nanowires

Abstract

The electronic properties of heterojunction electron gases formed in GaN/AlGaN core/shell nanowires with hexagonal and triangular cross-sections are studied theoretically. We show that at nanoscale dimensions, the non-polar hexagonal system exhibits degenerate quasi-one-dimensional electron gases at the hexagon corners, which transition to a core-centered electron gas at lower doping. In contrast, polar triangular core/shell nanowires show either a non-degenerate electron gas on the polar face or a single quasi-one-dimensional electron gas at the corner opposite the polar face, depending on the termination of the polar face. More generally, our results indicate that electron gases in closed nanoscale systems are qualitatively different from their bulk counterparts.