Mobility in N-Doped Wurtzite III-Nitrides

TL;DR

This paper investigates how electric fields affect the electron mobility in n-doped wurtzite III-Nitrides, analyzing various scattering mechanisms and their contributions to mobility reduction.

Contribution

It provides a detailed analysis of the nonequilibrium thermodynamic state and the dependence of mobility on electric field strength in III-Nitride semiconductors.

Findings

Mobility decreases as electric field strength increases.

Polar-optic interactions are the dominant scattering mechanism.

Other contributions include deformation, piezoelectric, and impurity interactions.

Abstract

A study of the mobility of n-doped wurtzite III-Nitrides is reported. We have determined the nonequilibrium thermodynamic state of the III-Nitrides systems, driven far away from equilibrium by a strong electric field, in the steady state, which follows after a very fast transient. The dependence of the mobility (which depends on the nonequilibrium thermodynamic state of the sample) on the electric field strength is derived, which decreases with the strength of electric field. We analyzed the contributions to the mobility arising out of the different channels of electron scattering, namely, the polar optic, deformation, piezoelectric, interactions with the phonons, and with impurities. The case of n-InN, n-GaN, and n-AlN have been analyzed: as expected the main contribution comes from the polar-optic interactions in these strongly polar semiconductors. The other interactions are in decreasing order, the deformation acoustic, the piezoelectric, and the one due to impurities.