Direct measurements of electron-longitudinal optical phonon scattering rates in wurtzite GaN

Electron-longitudinal optical phonon scattering rates in wurtzite GaN have been directly measured by subpicosecond time-resolved Raman spectroscopy. We find that the total electron-longitudinal optical phonon scattering rate in GaN is about one order of magnitude larger than that in GaAs. We attribute this enormous increase in the electron-longitudinal optical phonon scattering rate to the much larger ionicity in GaN.