Predicion of charge separation in GaAs/AlAs cylindrical Russian Doll nanostructures

TL;DR

This paper investigates charge separation in GaAs/AlAs nanostructures, comparing flat quantum wells with cylindrical 'Russian Doll' arrangements, and identifies configurations that enable charge separation through theoretical calculations.

Contribution

It introduces a theoretical analysis of cylindrical GaAs/AlAs nanostructures, revealing configurations that facilitate charge separation not present in flat quantum wells.

Findings

Charge separation can occur in cylindrical 'Russian Doll' nanostructures.

Specific layer configurations enable localization of CBM and VBM in different regions.

Theoretical pseudopotential calculations identify these configurations.

Abstract

We have contrasted the quantum confinement of (i) multiple quantum wells of flat GaAs and AlAs layers, i.e. $(\GaAs)_{m}/(\AlAs)_n/(\GaAs)_p/(\AlAs)_q$, with (ii) ``cylindrical Russian Dolls'' -- an equivalent sequence of wells and barriers arranged as concentric wires. Using a pseudopotential plane-wave calculation, we identified theoretically a set of numbers ($m,n,p$ and $q$) such that charge separation can exist in ``cylindrical Russian Dolls'': the CBM is localized in the inner GaAs layer, while the VBM is localized in the outer GaAs layer.