Large thermoelectric efficiency of doped polythiophene junction: a density functional study

TL;DR

This study uses density functional theory to show that doping polythiophene with Li or Cl significantly enhances its thermoelectric efficiency by altering molecular structure and electronic transmission, making it a promising thermoelectric device.

Contribution

It demonstrates the impact of specific dopants on the thermoelectric properties of polythiophene junctions through detailed theoretical analysis.

Findings

Dopants induce structural changes in polythiophene oligomers.

Dopants modify molecular energy levels and transmission spectra.

Enhanced thermopower and figure of merit observed in doped junctions.

Abstract

The thermoelectric properties of polythiophene (PT) coupled to the Au (111) electrodes are studied based on density functional theory combined with nonequilibrium Green function formalism. Specially, the effect of Li and Cl adsorbents on the thermoelectric efficiency of the PT junction is investigated in different concentrations of the dopants for two lengths of the PT. Results show that the presence of dopants can bring the structural changes in the oligomer and modify the arrangement of the molecular levels leading to the dramatic changes in the transmission spectra of the junction. Therefore, the large enhancement in thermopower and consequently figure of merit is obtained by dopants which makes the doped PT junction as a beneficial thermoelectric device.