Transport Properties of Epitaxial La_XBa_(1-X)SnO₃ through Off-Axis Sputtering

BaSnO₃ (BSO) is a n-type semiconducting perovskite that has garnered great interest due to its optical transparency, thermal stability, and high mobility at room temperature. In addition, the low lattice mismatch with ferroelectric perovskites provides easy integration into ferroelectric field effect transistors while maintaining crystalline quality. A major challenge to BaSnO₃ thin films is the difficulty in obtaining the high mobilities reported in its bulk counterpart. Many growth methods have been explored to increase the mobility at low doping concentrations.

In this work, we present the growth of epitaxial La-substituted BaSnO₃ (LBSO) films using off axis magnetron sputtering. Film quality was characterized by AFM, XRD, and TEM, showing high quality growth on SrTiO₃(001). Temperature dependent transport measurements are conducted for films grown with 1-5% La concentration to determine the carrier mobility in the lower doping regime. For the various lanthanum concentrations, a study of the O₂ partial pressure during deposition is done to understand the role of oxygen content on the electrical properties. Hall mobilities and carrier densities of LBSO were measured using Van Der Pauw and Hall bar geometry in a PPMS for varying lanthanum substitution and oxygen partial pressure.