Thermoelectric Energy Conversion: How Good Can Silicon Be?

TL;DR

This paper explores the potential of silicon as a thermoelectric material, demonstrating that thin-film silicon could achieve significantly higher efficiency than bulk silicon by reducing thermal conductivity through confinement effects.

Contribution

It models a thin-film silicon thermoelectric device showing a tenfold efficiency increase over bulk silicon, highlighting a promising approach for thermoelectric energy conversion.

Findings

High power density of 7W/cm2 at ΔT=30K modeled

10nm thick silicon shows 10 times higher efficiency than bulk

Confinement effects reduce thermal conductivity in thin films

Abstract

Lack of materials which are thermoelectrically efficient and economically attractive is a challenge in thermoelectricity. Silicon could be a good thermoelectric material offering CMOS compatibility, harmlessness and cost reduction but it features a too high thermal conductivity. High harvested power density of 7W/cm2 at deltaT=30K is modeled based on a thin-film lateral architecture of thermo-converter that takes advantage of confinement effects to reduce the thermal conductivity. The simulation leads to the conclusion that 10nm thick Silicon has 10 times higher efficiency than bulk.