Electronic Kapitza conductance and related kinetic coefficients at an interface between n-type semiconductors

TL;DR

This paper calculates the interfacial kinetic coefficients, including Kapitza conductance and Seebeck coefficient, for n-type semiconductor interfaces using Boltzmann transport theory, revealing potential for thermoelectric applications.

Contribution

It introduces the concept of electrochemical potential jump at semiconductor interfaces and calculates three kinetic coefficients for n-type semiconductors.

Findings

Kapitza conductance at semiconductor interfaces quantified.

Interfacial Seebeck coefficient can reach about 10^{-3} V/K.

Potential for thermoelectric material development identified.

Abstract

We calculate the Kapitza conductance, which is the proportionality coefficient between heat flux and temperature jump at the interface, for the case of two conducting solids separated by the interface. We show that for conducting solids in a non-equilibrium state, there should also arise the electrochemical potential jump at the interface. Hence to describe linear transport at the interface we need three kinetic coefficients: interfacial analogs of electric and heat conductances and interfacial analog of the Seebeck coefficient. We calculate these coefficients for the case of an interface between n-type semiconductors. We perform calculations in the framework of Boltzmann transport theory. We have found out that the interfacial analog of the Seebeck coefficient for some range of parameters of the considered semiconductors, has a high value of about $10^{-3}$ V/K. Thus this effect has the potential to be used for the synthesis of effective thermoelectric materials.