Thermoelectric Transport Coefficients in Mono-layer MoS2 and WSe2 Role of Substrate, Interface Phonons, Plasmon, and Dynamic Screening

TL;DR

This paper calculates thermoelectric transport coefficients in monolayer MoS2 and WSe2, considering substrate effects, phonons, plasmons, and dynamic screening, providing insights into how these factors influence thermoelectric performance.

Contribution

It introduces a comprehensive model that accounts for substrate-induced remote phonons, plasmons, and dynamic screening effects in TMDs, advancing understanding of their thermoelectric properties.

Findings

Transport coefficients vary with temperature and doping density.

Substrate type significantly affects thermoelectric properties.

Screening and remote phonon scattering influence electron transport.

Abstract

The thermoelectric transport coefficients of electrons in two recently emerged transition metal dichalcogenides(TMD), MoS2 and WSe2, are calculated by solving Boltzmann Transport equation and coupled electrical and thermal current equations using Rode iterative technique. Scattering from localized donor impurities, acoustic deformation potential, longitudinal optical (LO) phonons, and substrate induced remote phonon modes are taken into account. Hybridization of TMD plasmon with remote phonon modes is investigated. Dynamic screening under linear polarization response is explored in TMDs sitting on a dielectric environment and the screened electron-phonon coupling matrix elements are calculated. The effect of screening and substrate induced remote phonon mediated scattering on the transport coefficients of the mentioned materials is explained. The transport coefficients are obtained for a varying range of temperature and doping density for three different types of substrates SiO2, Al2O3, and HfO2. The thermoelectric properties of interest including Seebeck coefficient, Peltier coefficient, and electronic thermal conductivity are calculated.