Very high thermoelectric power factor in a Fe3O4/SiO2/p-type Si(100)heterostructure

TL;DR

This study reports a heterostructure with exceptionally high thermoelectric power factor due to carrier tunneling and interface effects, promising for thermoelectric applications.

Contribution

It demonstrates a novel Fe3O4/SiO2/p-Si(100) heterostructure exhibiting a record high thermoelectric power factor at room temperature.

Findings

Power factor of 25.5 mW/K²m at 260K

Sign change in Hall and Seebeck coefficients with temperature

Sharp resistivity drop due to tunneling into p-Si(100)

Abstract

The thermoelectric and transport properties of a Fe3O4/SiO2/p-Si(100) heterostructure have been investigated between 100 and 300 K. Both Hall and Seebeck coefficients change sign from negative to positive with increasing temperature while the resistivity drops sharply due to tunneling of carriers into the p-Si(100). The low resistivity and large Seebeck coefficient of Si give a very high thermoelectric power factor of 25.5mW/K2m at 260K which is an underestimated, lower limit value and is related to the density of states and difference in the work functions of Fe3O4 and Si(100) that create an accumulation of majority holes at the p-Si/SiO2 interface