Tailoring the core electron density in modulation-doped Core-Multi-Shell nanowires

TL;DR

This paper demonstrates how radial composition modulation in core-multi-shell nanowires enhances control over free-carrier density, overcoming doping tuning challenges through self-consistent calculations of electron distribution.

Contribution

It introduces a method to tailor electron density in nanowires by compositional modulation, improving doping control in high-mobility cores.

Findings

Radial composition modulation improves carrier control.

Electrons localize in outer shells, screening the core.

Enhanced doping tuning in nanowires.

Abstract

We show how a proper radial modulation of the composition of core-multi-shell nanowires critically enhances the control of the free-carrier density in the high-mobility core with respect to core-single-shell structures, thus overcoming the technological difficulty of fine tuning the remote doping density. We calculate the electron population of the different nanowire layers as a function of the doping density and of several geometrical parameters by means of a self-consistent Schr\"odinger-Poisson approach: Free carriers tend to localize in the outer shell and screen the core from the electric field of the dopants.