Enhancement of Carrier Mobility in Semiconductor Nanostructures by Dielectric Engineering

TL;DR

This paper demonstrates that coating semiconductor nanostructures with high-k dielectrics significantly enhances carrier mobility by reducing Coulombic impurity scattering, with potential improvements up to tenfold.

Contribution

It introduces a dielectric engineering technique that substantially improves carrier mobility in 2D and 1D semiconductor nanostructures by modifying their dielectric environment.

Findings

Carrier mobility can be increased by coating with high-k dielectrics.

Coulombic impurity scattering is effectively damped by dielectric modification.

Mobility improvements can reach up to an order of magnitude.

Abstract

We propose a technique for achieving large improvements in carrier mobilities in 2- and 1-dimensional semiconductor nanostructures by modifying their dielectric environments. We show that by coating the nanostructures with high-$\kappa$ dielectrics, scattering from Coulombic impurities can be strongly damped. Though screening is also weakened, the damping of Coulombic scattering is much larger, and the resulting improvement in mobilities of carriers can be as much as an order of magnitude for thin 2D semiconductor membranes, and more for semiconductor nanowires.