Scattering of Carriers by Charged Dislocations in Semiconductors

TL;DR

This paper analyzes how charged dislocations affect carrier mobility in semiconductors, providing new formulas for mobility, scattering times, and resistivity, with implications for experimental measurements.

Contribution

It introduces a new closed-form expression for carrier mobility valid across all temperatures considering anisotropic scattering.

Findings

Quantum and transport scattering time ratios are evaluated.

Hall scattering factor may be underestimated by a factor of two.

Derived expressions for resistivity tensor with tilted dislocations.

Abstract

The scattering of carriers by charged dislocations in semiconductors is studied within the framework of the linearized Boltzmann transport theory with an emphasis on examining consequences of the extreme anisotropy of the scattering potential. A new closed-form approximate expression for the carrier mobility valid for all temperatures is proposed. The ratios of quantum and transport scattering times are evaluated after averaging over the anisotropy in the relaxation time. The value of the Hall scattering factor computed for charged dislocation scattering indicates that there may be a factor of two error in the experimental mobility estimates using the Hall data. An expression for the resistivity tensor when the dislocations are tilted with respect to the plane of transport is derived. Finally an expression for the isotropic relaxation time is derived when the dislocations are located within the sample with a uniform angular distribution.