Semi-classical electronic transport properties of ternary compound AlGaAs$_2$: Role of different scattering mechanisms

TL;DR

This study investigates the semi-classical electron transport in AlGaAs2, highlighting the impact of different scattering mechanisms and crystal structures on electron mobility, with implications for high-mobility electronic devices.

Contribution

It provides a detailed analysis of scattering mechanisms in AlGaAs2 using Rode's iterative method, comparing two crystal phases and their effects on electron mobility.

Findings

Higher mobility in body centered tetragonal phase.

Polar optical phonon scattering dominates at room temperature.

Rode's iterative method yields higher mobility estimates than relaxation time approximation.

Abstract

We present a comprehensive investigation of semi-classical transport properties of n-type ternary compound AlGaAs2, using Rode's iterative method. Four scattering mechanisms, have been included in our transport calculation, namely, ionized impurity, piezoelectric, acoustic deformation and polar optical phonon (POP). The scattering rates have been calculated in terms of ab-initio parameters. We consider AlGaAs2 to have two distinct crystal geometries, one in tetragonal phase (space group: ), while the other one having body centered tetragonal crystal structure (space group:). We have observed higher electron mobility in the body centered tetragonal phase, thereby making it more suitable for high mobility device application, over the tetragonal phase. In order to understand the differences in electron moblities for these two phases, curvatures of the E-k graph of the conduction bands for these phases have been compared. At room temperature, the dominant contribution in electron mobility was found to be provided by inelastic POP scattering. We have also noted that mobility is underestimated in relaxation time approximation as compared with the Rode's iterative approach.