Strain Driven Anomalous Anisotropic Enhancement in the Thermoelectric Performance of monolayer MoS${}_2$

Abstract

First principles density functional theory based calculations have been performed to investigate the strain and temperature induced tunability of the thermoelectric properties of monolayer (ML) MoS${}_2$. Modifications in the electronic and phononic transport properties, under two anisotropic uniaxial strains along the armchair (AC) and zigzag (ZZ) directions, have been explored in detail. Considering the intrinsic carrier-phonon scattering, we found that the charge carrier mobility ($\mu$) and relaxation time ($\tau$) increase remarkably for strains along the ZZ direction. Concomitantly, strain along the ZZ direction significantly reduces the lattice thermal conductivity (${\kappa }_{\text{L}}$) of ML-MoS${}_2$. The combined effect of shortened phonon relaxation time and group velocity, and the reduced Debye temperature is found to be the driving force behind the lowering of ${\kappa }_{\text{L}}$. The large reduction in ${\kappa }_{\text{L}}$ and increase in $\tau$, associated with the strains along the ZZ direction, act in unison to result in enhanced efficiency and hence, improved thermoelectric performance. Nearly $150\%$ enhancement in the thermoelectric efficiency can be achieved with the optimal doping concentration. We, therefore, highlight the significance of in-plane tensile strains, in general, and strains along the ZZ direction, in particular, in improving the thermoelectric performance of ML-MoS${}_2$.

arXiv comment12 pages, 6 captioned figures

References in corpus (22)

• BoltzTraP. A code for calculating band-structure dependent quantities
• Bandgap Engineering of Strained Monolayer and Bilayer MoS2
• Quantum Spin Hall Effect and Topological Field Effect Transistor in Two-Dimensional Transition Metal Dichalcogenides
• Distribution of phonon lifetime in Brillouin zone
• Local strain engineering in atomically thin MoS2
• Efficient calculation of carrier scattering rates from first principles
• Large and tunable photo-thermoelectric effect in single-layer MoS2
• Lattice Vibrational Modes and Phonon Thermal Conductivity of Monolayer MoS2
• Strain tuning of optical emission energy and polarization in monolayer and bilayer MoS2
• Electronic and Thermoelectric Properties of Few-Layer Transition Metal Dichalcogenides
• Thermal conductivity of monolayer MoS2, MoSe2, and WS2: Interplay of mass effect, interatomic bonding and anharmonicity
• High Thermoelectric Powerfactor in Single and Few-Layer MoS${}_2$
• Strain-induced enhancement of thermoelectric performance in a ZrS2 monolayer
• Low-Dimensional Transport and Large Thermoelectric Power Factors in Bulk Semiconductors by Band Engineering of Highly Directional Electronic States
• Phonon transport of Janus monolayer MoSSe: a first-principles study
• A Revisit to High Thermoelectric Performance of Single-layer MoS2
• Role of Strain on Electronic and Mechanical Response of Semiconducting Transition-Metal Dichalcogenide Monolayers: an ab-initio study
• Two-dimensional MoS${}_2$ electromechanical actuators
• Effect of strain on electronic and thermoelectric properties of few layers to bulk MoS${}_2$
• High pressure effect on structure, electronic structure and thermoelectric properties of MoS${}_2$
• Gate-Tunable and Thickness-dependent Electronic and Thermoelectric Transport in few-layer MoS2
• The Buckling of Single-Layer MoS2 Under Uniaxial Compression

Cited by in corpus (1)

• Ab-initio Study of Electronic and Lattice Dynamical Properties of monolayer ZnO under Strain