Thermoelectric and lattice dynamics properties of layered MX (M = Sn, Pb; X = S, Te) compounds

Abstract

Lead and tin chalcogenides have been studied widely due to their promising thermoelectric (TE) properties. Further enhancement in their TE efficiency has been reported upon the reduction of the dimension, which is an important feature in modern device fabrications. Using density functional theory combined with the Semi-classical Boltzmann transport theory, we studied the structural, electronic and TE properties of two-dimensional (2D) MX (M = Sn, Pb; X = S, Te) monolayers. Spin-orbit coupling was found to have significant effects on their electronic structure, particularly for the heavy compounds. Structural optimization followed by phonon transport studies prevailed that the rectangular (γ-) phase is energetically the most favorable for SnS and SnTe monolayers, whereas the square structure is found the most stable for PbS and PbTe monolayers. Our results are in good agreement with previous studies. These 2D materials exhibit high Seebeck coefficients and power factors along with low lattice thermal conductivities, which are essential features of good TE materials. The maximum figure of merits (ZT) of 1.04, 1.46, 1.51 and 1.94 are predicted for n-type SnS, SnTe, PBS and p-type PbTe monolayers respectively at 700 K, which are higher than their bulk ZT values. Hence, these monolayers are promising candidates for TE applications.

References in corpus (14)

• Two-Dimensional Gas of Massless Dirac Fermions in Graphene
• Van der Waals density functionals applied to solids
• Two-dimensional materials from high-throughput computational exfoliation of experimentally known compounds
• High Performance Single Layered WSe2 p-FETs with Chemically Doped Contacts
• BoltzTraP2, a program for interpolating band structures and calculating semi-classical transport coefficients
• Phosphorene analogues: isoelectronic two-dimensional group-IV monochalcogenides with orthorhombic structure
• Anisotropic intrinsic lattice thermal conductivity of phosphorene from first principles
• Phonon Transport in Single-Layer Transition Metal Dichalcogenides: a First-Principles Study
• Diverse anisotropy of phonon transport in two-dimensional IV-VI compounds: A comparative study
• Two-dimensional disorder in black phosphorus and monochalcogenide monolayers
• New two-dimensional phase of tin chalcogenides: candidates for high-performance thermoelectric materials
• Water splits to degrade two-dimensional group-IV monochalcogenides in nanoseconds
• From atomic layer to the bulk: low-temperature atomistic structure, ferroelectric and electronic properties of SnTe films
• The effect of hydrostatic pressure and uniaxial strain on the electronic structure of Pb${}_{\text{1-x}}$Sn${}_{\text{x}}$Te

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