Reduced sub-picosecond electron relaxation in GaNAs

We report on time resolved femtosecond carrier dynamics in molecular beam epitaxy (MBE) grown GaNxAs1-x with a nitrogen fraction of 1.3 %. The intraband carrier relaxation time in GaNxAs1-x is found to be significantly larger than in GaAs. We compare the experimental results with carrier ? polar optical phonon scattering rates calculated within the band anticrossing model. From the results we conclude that the slowing down of the carrier relaxation is a result of the strongly modified band structure in GaNxAs1-x.