# Leveraging Electron-Phonon Interaction to Enhance Thermoelectric Power Factor in Graphene-Like Semimetals

## TL;DR

This paper demonstrates that strong, energy-dependent electron-phonon interactions can be harnessed to significantly boost the thermoelectric power factor in graphene-like semimetals by enabling electron energy filtering.

## Contribution

It introduces a novel approach to enhance thermoelectric performance by engineering electron-phonon interactions in 2D Dirac materials, supported by first-principles calculations.

## Key findings

- Enhanced EPI increases Seebeck coefficient and power factor.
- Optimal heavy state placement at the Dirac point maximizes filtering.
- Potential to achieve ultrahigh power factors through EPI engineering.

## Abstract

Electron-phonon interaction (EPI) is presumably detrimental for thermoelectric performance in semiconductors because it limits carrier mobility. Here we show that enhanced EPI with strong energy dependence offers an intrinsic pathway to significant increase in the Seebeck coefficient and the thermoelectric power factor, particularly in the context of two-dimensional (2D) graphene-like Dirac bands. The increase is realized by enabling electron energy filtering through preferential scattering of electron/hole carriers. We prove this concept by implementing state-of-the-art first-principles computational methods with explicit treatment of EPI for a 2D gapless MoS$_{2}$ allotrope, which has both massless Dirac bands and a heavy-fermion state that acts as the filter. We determine that the optimal location of the heavy state and hence the onset of the filtering process is at the Dirac point. Our study opens a new avenue for attaining ultrahigh power factors via engineering the EPI in graphene-like semimetals or identifying new compounds that intrinsically possess the featured electronic structure.