Reference : First-principles modeling of the thermoelectric properties of SrTiO3/SrRuO3 superlattices
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Physics
http://hdl.handle.net/2268/129394
First-principles modeling of the thermoelectric properties of SrTiO3/SrRuO3 superlattices
English
Garcia-Fernandez, Pablo []
Verissimo-Alves, Marcos []
Bilc, Daniel mailto [Université de Liège - ULg > Département de physique > Physique théorique des matériaux >]
Ghosez, Philippe mailto [Université de Liège - ULg > Département de physique > Physique théorique des matériaux >]
Junquera, Javier []
Aug-2012
Physical Review. B, Condensed Matter and Materials Physics
American Physical Society
86
085305
Yes (verified by ORBi)
International
1098-0121
1550-235X
Woodbury
NY
[en] Using a combination of first-principles simulations, based on density functional theory and Boltzmann’s semiclassical theory, we have calculated the transport and thermoelectric properties of the half-metallic twodimensional electron gas confined in single SrRuO3 layers of SrTiO3/SrRuO3 periodic superlattices. Close to the Fermi energy, we find that the semiconducting majority-spin channel displays a very large in-plane component of the Seebeck tensor at room temperature, S ∼ 1500 μV/K, and the minority-spin channel shows good in-plane conductivity, σ = 2.5 (m cm)−1. However, we find that the total power factor and thermoelectric figure of
merit for reduced doping is too small for practical applications. Our results support that the confinement of the electronic motion is not the only thing that matters to describe the main features of the transport and thermoelectric properties with respect the chemical doping, but the shape of the electronic density of states, which in our case departs from the free-electron behavior, is also important. The evolution of the electronic structure, electrical conductivity, Seebeck coefficient, and power factor as a function of the chemical potential is explained by a simplified tight-binding model. We find that the electron gas in our system is composed by a pair
of one-dimensional electron gases orthogonal to each other. This reflects the fact the physical dimensionality of the electronic system (1D) can be even smaller than that of the spacial confinement of the carriers (2D).
Researchers ; Professionals ; Students
http://hdl.handle.net/2268/129394
10.1103/PhysRevB.86.08505

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