High thermoelectric power factor in LaVO3/KTaO3 heterostructure

Abstract

Perovskite oxides are well-known for exhibiting semiconducting properties and widely used for electronic applications. The combination of two different perovskite oxides form heterojunction interface that tailors the charge transfer mechanism. Here, the thermoelectric(TE) electrical transport properties are investigated of pervoskite oxide heterostructure (HS) L a V O 3 / K T a O 3 ( L V O / K T O ) using Boltzmann transport equation (BTE) for symmetric and asymmetric termination in [001] orientation. The electron–phonon scattering and defect scattering due to oxygen vacancies are incorporated with BTE. A strong electron–phonon scattering is observed. The effect of oxygen defect concentration on electrical transport is also studied. These HS exhibits high electrical conductivity 2 . 9 × 1 0 4 S/m at room temperature due to n-type conducting interface and highly dispersive degenerate conduction bands. Besides moderate Seebeck coefficient, a relatively high thermoelectric power factor of 222 μ V m − 1 K − 2 for symmetric termination HS is obtained at 300 K as compared to bulk K T a O 3 and S r T i O 3 . The high power factor and low electronic thermal conductivity (0.19 Wm − 1 K − 1 ) designate L V O / K T O HS as an efficient material for photothermoelectric-based detectors and photovoltaic applications. • Electrical transport is predicted using Boltzmann transport theory. • Defect scattering due to oxygen vacancies is implemented. • Electron phonon scattering dominant at all temperatures. • High electrical conductivity of 2.9 x 10 4 S/m is obtained at 300 K. • Enhancement in power factor compared to bulk KTO and STO.