Low-temperature electron mobility in doped semiconductors with high dielectric constant

TL;DR

This paper introduces a new theoretical mechanism for electron-impurity scattering in doped semiconductors with high dielectric constants, explaining low-temperature mobility behavior consistent with experimental data.

Contribution

It proposes a novel scattering mechanism based on vector lattice deformations caused by impurities, which accounts for observed mobility scaling in certain materials.

Findings

Mobility scales as μ(n) ∝ n^{-2/3} at low temperatures.

The mechanism aligns with experimental observations in relevant materials.

Deformation decay follows a 1/r^2 law from impurities.

Abstract

We propose and study theoretically a new mechanism of electron-impurity scattering in doped seminconductors with large dielectric constant. It is based upon the idea of \textit{vector} character of deformations caused in the crystalline lattice by any point defects siting asymmetrically in the unit cell. In result, local lattice compression due to the elastic deformations decay as $1/r^2$ with distance from impurity. Electron scattering (due to standard deformation potential) on such defects leads to low-temperature mobility $\mu(n)$ scaling with electron density $n$ of the form $\mu(n) \propto n^{-2/3}$ that is close to experimental observations on a number of relevant materials.