Modulation of Charge Transport at Grain Boundaries in SrTiO₃: Toward a High Thermoelectric Power Factor at Room Temperature.

ABSTRACT: Modulation of the grain boundary properties in thermoelectric materials that have thermally activated electrical conductivity is crucial in order to achieve high performance at low temperatures. In this work, we show directly that the modulation of the potential barrier at the grain boundaries in perovskite SrTiO₃ changes the low-temperature dependency of the bulk material's electrical conductivity. By sintering samples in a reducing environment of increasing strength, we produced La_0.08Sr_0.9TiO₃ (LSTO) ceramics that gradually change their electrical conductivity behavior from thermally activated to single-crystal-like, with only minor variations in the Seebeck coefficient. Imaging of the surface potential by Kelvin probe force microscopy found l

SUBMITTER: Cao J 

PROVIDER: S-EPMC8023519 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature