First principle study of thermoelectric properties of La doped SrZrO3 perovskite

Abstract

Strontium zirconate is a material of great interest due to outstanding mechanical, thermal, chemical and electrical properties. This material has been known for its high dielectric constant, high breakdown strength, low leakage current density and wide bandgap. Strontium zirconate is good candidate for thermoelectric applications due to its nontoxic, inexpensive and environment-friendly nature. In this work, we conducted a first principle study on thermoelectric properties of La doped SrZrO3 with 12.5 % concentration using CASTEP, BoltzTraP and Phono3py packages. The band structure analysis shown that La doped SrZrO3 exhibits semi metallic behaviour. The Seebeck coefficient analysis of La doped SrZrO3 showed that it has n typed carrier but with reduced magnitude due to higher carrier density. The conductivity of La doped SrZrO3 also increased significantly due to higher carrier density, and this reflected in the increases of the electronic thermal conductivity and overall thermal conductivity of La doped compound. The improvement in conductivity also lead to improvement of the figure of merit (ZT) of La doped SrZrO3 to 0.23 at 900 K.