Electron mobility in GaN

Electron mobility in GaN have been studied experimentally and theoretically. All important scattering mechanisms, i.e. impurity, polar optical phonon, acoustic-phonon, piezoelectric, and dislocation are included in the calculation. It has been found that extended defects, like dislocation plays important role on the mobility of electron in GaN. Ionized impurity scattering has been treated beyond the Born approximation using a phase-shift analysis. The compensation ratio is used as a parameter with a realistic charge neutrality condition. Comparisons with experimental data confirm the present calculation over a wide range of temperatures. Mobility and electron concentration data from Ball measurements reveal a degenerate layer either due to disordered interface layer or due to impurity band.