Ultrafast carrier - carrier scattering in wide-gap GaN semiconductor laser devices

The carrier - carrier scattering rates for GaN quantum-well optical amplifiers at typical lasing densities are calculated from first principles using quantum kinetic Boltzmann equations in the Markovian limit. Because of the large excitonic binding energies inherent in GaN and the effective mass properties, heavy-hole valence-band scattering rates are calculated to be in excess of (corresponding scattering time <15 fs). A comparison to GaAs is also made which yields significantly lower scattering rates of around (30 - 160 fs).