High Mobility in a Stable Transparent Perovskite Oxide

TL;DR

This paper reports the discovery of La-doped BaSnO3 with record-high room-temperature mobility and excellent stability, making it a promising material for transparent high-frequency and high-power devices.

Contribution

It demonstrates unprecedented high mobility in La-doped BaSnO3 and its stability under thermal cycling, advancing transparent oxide semiconductor technology.

Findings

Room-temperature mobility of 320 cm^2(Vs)^-1 in single crystals

Maximum mobility of 70 cm^2(Vs)^-1 in epitaxial films

Resistance remains stable after thermal cycling to 530°C in air

Abstract

We discovered that La-doped BaSnO3 with the perovskite structure has an unprecedentedly high mobility at room temperature while retaining its optical transparency. In single crystals, the mobility reached 320 cm^2(Vs)^-1 at a doping level of 8x10^19 cm^-3, constituting the highest value among wide-band-gap semiconductors. In epitaxial films, the maximum mobility was 70 cm^2(Vs)^-1 at a doping level of 4.4x10^20 cm^-3. We also show that resistance of (Ba,La)SnO3 changes little even after a thermal cycle to 530 Deg. C in air, pointing to an unusual stability of oxygen atoms and great potential for realizing transparent high-frequency, high-power functional devices.