Wide bandgap perovskite oxides with high room temperature conductivities and structural compatibility with a diverse family of organic/inorganic perovskite materials are of significant interest as transparent conductors and as active components in power electronics. Such materials must also possess high room temperature mobility to minimize power consumption and to enable high-frequency applications. Here, we report n-type BaSnO₃ films grown using hybrid molecular beam epitaxy with room temperature conductivity exceeding 10⁴ S cm^-1. Significantly, these films show room temperature mobilities up to 120 cm² V^-1 s^-1 even at carrier concentrations above 3 × 10²⁰ cm^-3 together with a wide bandgap (3 eV). We examine the mobility-limiting scattering mechanisms by calculating temperature-dependent mobility, and Seebeck coefficient using the Boltzmann transport framework and ab-initio calculations. These results place perovskite oxide semiconductors for the first time on par with the highly successful III-N system, thereby bringing all-transparent, high-power oxide electronics operating at room temperature a step closer to reality.

We have explored the effect of magnetic rare-earth dopants substitutionally incorporated on the Ba sites of BaSnO3 in terms of electronic transport, magnetism, and optical properties. We show that for Ba0.92R0.08SnO3 thin films (where R=La,Pr,Nd,Gd), there is a linear increase of mobility with carrier concentration across all doping schemes. La-doped films have the highest mobilities, followed by Pr- and Nd-doped films. Gd-doped samples have the largest ionic size mismatch with the Ba site and correspondingly the lowest carrier concentrations and electron mobilities. However, crystallinity does not appear to be a strong predictor of transport phenomena; our results suggest that point defects more than grain boundaries are key ingredients in tuning the conduction of BaSnO3 films grown by pulsed laser deposition. Pronounced, nonhysteretic x-ray magnetic dichroism signals are observed for Pr-, Nd-, and Gd-doped samples, indicating paramagnetism. Finally, we probe the optical constants for each of the BaSnO3 doping schemes and note that there is little change in the transmittance across all samples. Together these results shed light on conduction mechanisms in BaSnO3 doped with rare-earth cations.