Large effects of dislocations on high mobility of epitaxial perovskite Ba_0.96La_0.04SnO₃ films

Abstract

We studied the relationship between the mobility and dislocation density for recently discovered high-mobility Ba0.96La0.04SnO3 thin-films and found that the carrier density and mobility of the film, as high as 4.0×1020 cm−3 and 70 cm2 V−1s−1, respectively, decreased as the dislocation density increased. We determined the values for dislocation density using transmission electron microscopy and atomic force microscopy after surface etching. We found that the effect of dislocations on the mobility was large, when compared with that for GaN with a similar dislocation density. The importance of dislocation scattering in the perovskite structure is emphasized, especially in a low-carrier-density regime.