# Hole mobility of strained GaN from first principles

## TL;DR

This study uses first-principles calculations to analyze phonon-limited hole mobility in strained GaN, revealing potential methods to enhance mobility by manipulating band structures through strain or optical excitation.

## Contribution

It introduces a comprehensive ab initio approach to predict hole mobility in GaN and proposes strain and optical methods to improve it.

## Key findings

- Mobility is mainly limited by acoustic deformation-potential scattering.
- Hole mobility can be increased by lifting split-off hole states.
- Strain or optical excitation can reverse crystal-field splitting to enhance mobility.

## Abstract

Nitride semiconductors are ubiquitous in optoelectronic devices such as LEDs and Blu-Ray optical disks. A major limitation for further adoption of GaN in power electronics is its low hole mobility. In order to address this challenge, here we investigate the phonon-limited mobility of wurtzite GaN using the ab initio Boltzmann transport formalism, including all electron-phonon scattering processes, spin-orbit coupling, and many-body quasiparticle band structures. We demonstrate that the mobility is dominated by acoustic deformation-potential scattering, and we predict that the hole mobility can significantly be increased by lifting the split-off hole states above the light and heavy holes. This can be achieved by reversing the sign of the crystal-field splitting via strain or via coherent excitation the A$_1$ optical phonon through ultrafast infrared optical pulses.