Nanogranular Thermoelectrics

TL;DR

This paper studies how electron-electron interactions in nano-granular materials influence thermopower and thermoelectric efficiency at intermediate temperatures, revealing size-dependent enhancements relevant for thermoelectric applications.

Contribution

It provides a theoretical analysis of thermopower in nano-granular materials with large tunneling conductance, highlighting the impact of electron-electron interactions at intermediate temperatures.

Findings

Thermopower increases as grain size decreases at T >= g_{T}elta.

The figure of merit varies with system parameters and temperature.

Electron-electron interactions significantly affect thermoelectric properties.

Abstract

We investigate thermopower and thermoelectric coefficient of nano-granular materials at large tunneling conductance between the grains, g_{T} >> 1. We show that at intermediate temperatures, T >= g_{T}\delta, where \delta is the mean energy level spacing for a single grain, electron-electron interaction leads to an increase of the thermopower with decreasing grain size. We discuss our results in the light of new types of thermoelectric materials and present the behavior of the figure of merit depending on system parameters.