Electron mobility of SnO2 from first principles

TL;DR

This study uses first-principles calculations to analyze the electron mobility of SnO2, revealing anisotropic transport properties and dominant scattering mechanisms across different doping levels and temperatures.

Contribution

It provides a detailed first-principles analysis of electron mobility in SnO2, including temperature and doping dependence, and identifies key scattering mechanisms affecting transport.

Findings

Mobility is strongly anisotropic, favoring the c-axis direction.

Polar-optical phonon scattering dominates at room temperature.

Ionized-impurity scattering becomes significant above 10^18 cm^-3.

Abstract

The transparent conducting oxide SnO2 is a wide bandgap semiconductor that is easily n-type doped and widely used in various electronic and optoelectronic applications. Experimental reports of the electron mobility of this material vary widely depending on the growth conditions and doping concentrations. In this work, we calculate the electron mobility of SnO2 from first principles to examine the temperature- and doping-concentration dependence, and to elucidate the scattering mechanisms that limit transport. We include both electron-phonon scattering and electron-ionized impurity scattering to accurately model scattering in a doped semiconductor. We find a strongly anisotropic mobility that favors transport in the direction parallel to the c-axis. At room temperature and intrinsic carrier concentrations, the low-energy polar-optical phonon modes dominate scattering, while ionized-impurity scattering dominates above 10^18 cm^-3.