Prediction of the High Thermoelectric Performance of Pnictogen Dichalcogenide Layered Compounds with Quasi-One-Dimensional Gapped Dirac-like Band Dispersion

Abstract

Thermoelectric power generation has been recognized as one of the most important technologies, and high-performance thermoelectric materials have long been pursued. However, because of the large number of candidate materials, this quest is extremely challenging, and it has become clear that a firm theoretical concept from the viewpoint of band-structure engineering is needed. In this study, we theoretically demonstrate that pnictogen-dichalcogenide layered compounds, which originally attracted attention as a family of superconductors and have recently been investigated as thermoelectric materials, can exhibit very high thermoelectric performance with elemental substitution. In particular, we clarify a promising guiding principle for materials design and find that LaOAsSe${}_2$, a material that has yet to be synthesized, has a powerfactor that is six times as large as that of the known compound LaOBiS${}_2$ and can exhibit a very large $ZT$ under some plausible assumptions. This large enhancement of the thermoelectric performance originates from the quasi-one-dimensional gapped Dirac-like band dispersion, which is realized by the square-lattice network. Our study offers one ideal limit of the band structure for thermoelectric materials. Because our target materials have high controllability of constituent elements and feasibility of carrier doping, experimental studies along this line are strongly awaited.

12 pages, 6 figures

References in corpus (10)

• "Pudding mold" band drives large thermopower in Na${}_x$CoO${}_2$
• Quantum Hall effect in a bulk antiferromagnet EuMnBi${}_2$ with magnetically confined two-dimensional Dirac fermions
• Minimal electronic models for superconducting BiS${}_2$ layers
• Transport Properties and Diamagnetism of Dirac Electrons in Bismuth
• Effect of Eu magnetism on the electronic properties of the candidate Dirac material EuMnBi2
• Interplay of Dirac electrons and magnetism in AMnBi2 (A=Ca, Sr)
• Enhancement of thermoelectric properties by Se substitution in layered bismuth-chalcogenide LaOBiS2-xSex
• Proximity to Fermi-surface topological change in superconducting LaO0.54F0.46BiS2
• Large magnetothermopower effect in Dirac materials (Sr/Ca)MnBi2
• Effect of high pressure annealing on the normal state transport of LaO0.5F0.5BiS2

Cited by in corpus (6)

• Enhancing thermopower and Nernst signal of high-mobility Dirac carriers by Fermi level tuning in the layered magnet EuMnBi${}_2$
• Enhanced thermoelectricity by controlled local structure in bismuth-chalcogenides
• First-principles study of defect formation energies in LaO$X$S${}_2$ ($X=$ Sb, Bi)
• Effect of Bi Substitution on Thermoelectric Properties of SbSe2-based Layered Compounds NdO${}_{0.8}$F${}_{0.2}$Sb${}_{1-x}$Bi${}_x$Se${}_2$
• Crystal Structure and Thermoelectric Transport Properties of As-Doped Layered Pnictogen Oxyselenides NdO0.8F0.2Sb1-xAsxSe2
• Possible high thermoelectric power factor in alkali-metal-intercalated BC${}_3$: anisotropic multiple valleys originating from the van Hove singularity of graphene