Thermopower of correlated semiconductors : application to FeAs2 and FeSb2

Abstract

We investigate the effect of electronic correlations onto the thermoelectricity of semi-conductors and insulators. Appealing to model considerations, we study various many-body renormalizations that enter the thermoelectric response. We find that, contrary to the case of correlated metals, correlation effects do not per se enhance the Seebeck coefficient or the figure of merit, for the former of which we give an upper bound in the limit of vanishing vertex corrections. For two materials of current interest, FeAs2 and FeSb2, we compute the electronic structure and thermopower. We find FeAs2 to be well described within density functional theory, and the therefrom deduced Seebeck coefficient to be in quantitative agreement with experiment. The capturing of the insulating ground state of FeSb2, however, requires the inclusion of many-body effects, in which we succeed by applying the GW approximation. Yet, while we get qualitative agreement for the thermopower of FeSb2 at intermediate temperatures, the tremendously large Seebeck coefficient at low temperatures is found to violate our upper bound, suggesting the presence of decisive (e.g. phonon mediated) vertex corrections.

15 pages, 6 figures

References in corpus (13)

• Quasiparticle self-consistent $GW$ method; a basis for the independent-particle approximation
• Screened Coulomb interaction in the maximally localized Wannier basis
• Optical properties of correlated materials -- Generalized Peierls approach and its application to VO2
• Huge Thermoelectric Power Factor: FeSb2 versus FeAs2 and RuSb2
• Temperature dependent correlations in covalent insulators
• The semiconductor-to-ferromagnetic-metal transition in FeSb2
• Correlations in a band insulator
• Anisotropy in magnetic and transport properties of Fe1-xCoxSb2
• Realistic many-body models for Manganese Monoxide under pressure
• Giant Carrier Mobility in Single Crystals of FeSb2
• Effective Coulomb interactions in solids under pressure
• Weak Ferromagnetism in Fe1-xCoxSb2
• Transport properties of heavy-fermion systems

Cited by in corpus (15)

• Prediction of unconventional magnetism in doped FeSb2
• Topotactic hydrogen in nickelate superconductors and akin infinite-layer oxides ABO2
• Unified picture for the colossal thermopower compound FeSb${}_2$
• Electronic thermoelectric power factor and metal-insulator transition in FeSb2
• Electronic correlations in FeGa${}_3$ and the effect of hole doping on its magnetic properties
• Vacancy defect control of colossal thermopower in FeSb2
• Resistivity saturation in Kondo insulators
• Maximum entropy analytic continuation for frequency-dependent transport coefficients with non-positive spectral weight
• Extraordinary Bulk Insulating Behavior in the Strongly Correlated Materials FeSi and FeSb${}_2$
• LinReTraCe: The Linear Response Transport Centre
• Enhancement of the effective disorder potential and the thermopower in Na${}_x$CoO${}_2$ through the electron-phonon coupling
• Optical conductivity and vibrational spectra of the narrow-gap semiconductor FeGa${}_3$
• Universal transport at Lifshitz metal-insulator transitions in two dimensions
• Prototypical many-body signatures in transport properties of semiconductors
• Origin of anomalous temperature dependence of Nernst effect in narrow-gap semiconductors