Absorbing/Emitting Phonons with one dimensional MOSFETs

TL;DR

This paper models heat exchange in one-dimensional nanowire FETs, revealing how bias voltage and Fermi level position influence local heat flows and suggesting potential for nanoscale heat management using nanowire arrays.

Contribution

It introduces a model for phonon-electron interactions in nanowire FETs, highlighting how bias and Fermi level position affect heat flow patterns, with implications for nanoscale thermal control.

Findings

Heat exchanges fluctuate randomly near the band center.

Heat currents flow from substrate to nanowire near band edges.

Arrays of nanowires could enable field-controlled phonon emission/absorption.

Abstract

We consider nanowires in the field effect transistor device configuration. Modeling each nanowire as a one dimensional lattice with random site potentials, we study the heat exchanges between the nanowire electrons and the substrate phonons, when electron transport is due to phonon-assisted hops between localized states. Shifting the nanowire conduction band with a metallic gate induces different behaviors. When the Fermi potential is located near the band center, a bias voltage gives rise to small local heat exchanges which fluctuate randomly along the nanowire. When it is located near one of the band edges, the bias voltage yields heat currents which flow mainly from the substrate towards the nanowire near one boundary of the nanowire, and in the opposite direction near the other boundary. This opens interesting perspectives for heat management at submicron scales: Arrays of parallel gated nanowires could be used for a field control of phonon emission/absorption.