Electron effective mass and mobility limits in degenerate perovskite stannate BaSnO$_3$

TL;DR

This study investigates the electron effective mass and mobility in BaSnO$_3$, revealing how doping affects these properties and demonstrating its potential as a high-mobility wide band gap semiconductor.

Contribution

It provides a comprehensive analysis of free carrier absorption and scattering mechanisms in BaSnO$_3$, explaining mobility limits and potential for improved performance.

Findings

Optical band gap widens with conduction band filling

Mobility limits are explained by scattering mechanisms

BaSnO$_3$ outperforms other wide band gap semiconductors

Abstract

The high room temperature mobility and the electron effective mass in BaSnO$_3$ are investigated in depth by evaluation of the free carrier absorption observed in infrared spectra for epitaxial films with free electron concentrations from $8.3 \times 10^{18}$ to $7.3 \times 10^{20}$~cm$^{-3}$. Both the optical band gap widening by conduction band filling and the carrier scattering mechanisms in the low and high doping regimes are consistently described employing parameters solely based on the intrinsic physical properties of BaSnO$_3$. The results explain the current mobility limits in epitaxial films and demonstrate the potential of BaSnO$_3$ to outperform established wide band gap semiconductors also in the moderate doping regime.