Mobility-electron density relation probed via controlled oxygen vacancy doping in epitaxial BaSnO3

The recently discovered high room temperature mobility in wide band gap semi-conducting BaSnO3 is of exceptional interest for perovskite oxide heterostructures. Critical open issues with epitaxial films include determination of the optimal dopant and understanding the mobility-electron density (mu-n) relation. These are addressed here through a transport study of BaSnO3(001) films with oxygen vacancy doping controlled via variable temperature vacuum annealing. Room temperature n can be tuned from 5 x 10(19) cm(-3) to as low as 2 x 10(17) cm(-3), which is shown to drive a weak- to strong-localization transition, a 10(4)-fold increase in resistivity, and a factor of 28 change in mu. The data reveal alpha proportional to n(0.65) scaling over the entire n range probed, important information for understanding mobility-limiting scattering mechanisms. (C) 2017 Author(s).