Effect of lattice distortions on the electron and thermal transport properties of transparent oxide semiconductor Ba1-x Sr x SnO3 solid solution films

Abstract

La-doped ASnO3 (A = Ba and Sr) have great potential as advanced transparent oxide semiconductors due to their large optical bandgap and relatively high electron mobility. The bandgap of Ba1-xSrxSnO3 solid solution increases from 3.2 eV (BaSnO3) to 4.6 eV (SrSnO3) with x. However, the increase in the bandgap is accompanied by reductions in the electrical conductivity. The versatility in the changes in the electrical properties is not trivial, and property optimization has been challenging. Here, we propose a simple metric for quantifying the transport properties of ASnO3. We investigated the electron/thermal transport properties of Ba1-xSrxSnO3 solid solution films and their relationship with the lattice distortion. The results suggest that all the transport properties of Ba1-xSrxSnO3 are dominated by the lattice distortion. This phenomenon is attributed to the distortions in the SnO6 octahedron, which consists of the conduction band.