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

摘要

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