Electron Transport Characteristics of Wurtzite GaN

F M Abou El-Ela,A Z Mohamed

doi:10.1155/2013/654752

Abstract

A three-valley Monte Carlo simulation approach was used to investigate electron transport in wurtzite GaN such as the drift velocity, the drift mobility, the average electron energy, energy relaxation time, and momentum relaxation time at high electric fields. The simulation accounted for polar optical phonon, acoustic phonon, piezoelectric, intervalley scattering, and Ridley charged impurity scattering model. For the steady-state transport, the drift velocity against electric field showed a negative differential resistance of a peak value of 2.9×105 m/s at a critical electric field strength 180×105 V/m. The electron drift velocity relaxes to the saturation value of 1.5×105 m/s at very high electric fields. The electron velocities against time over wide range of electric fields are reported.

Highlights

In recent years, most electronic and optoelectronic devices have been realized using alloys of the III–V nitrides, gallium nitride (GaN), aluminum nitride (AlN), and indium nitride (InN) [1, 2]
In 1975, Littlejohn et al [9] were the first to report results obtained from semiclassical Monte Carlo simulations of the steadystate electron transport within bulk wurtzite GaN
We examine transient electron transport in bulk wurtzite GaN for a variety of applied field strengths

Summary

Introduction

Most electronic and optoelectronic devices have been realized using alloys of the III–V nitrides, gallium nitride (GaN), aluminum nitride (AlN), and indium nitride (InN) [1, 2]. In 1975, Littlejohn et al [9] were the first to report results obtained from semiclassical Monte Carlo simulations of the steadystate electron transport within bulk wurtzite GaN. In 1993, Gelmont et al [10] reported on ensemble semiclassical two-valley Monte Carlo simulations of the electron transport within bulk wurtzite GaN; this analysis improvs upon the analysis of Littlejohn et al [9], by incorporating intervalley scattering into the simulations. In 1998, Albrecht et al [13] reported on employing ensemble semiclassical five-valley Monte Carlo simulations of the electron transport within bulk wurtzite GaN, with the aim of determining elementary analytical expressions for a number of electron transport parameters corresponding to bulk wurtzite GaN. Transport properties of GaN at both steady state and transient state has been discussed extensively over the year; uncertainty in material band parameters remains a key source of ambiguity in analysis of the electron transport properties

Monte Carlo Simulation

Charged Ionized Impurity Scattering Rate

Results and Discussion

Conclusions