Femtosecond studies of carrier dynamics in InGaN

Ultrafast carrier dynamics in ${\mathrm{In}}_{\text{0.16}}{\mathrm{Ga}}_{\text{0.84}}\mathrm{N}$ were investigated using femtosecond transient transmission measurements. We observed a fast initial carrier cooling on a time scale of 500 fs followed by a slow relaxation process which persisted longer than 5 ps due to a hot phonon effect. Band gap renormalization induced transient absorption was observed using a probe photon energy 300 meV above the band edge. These results were compared to a model based on the numerical resolution of the carrier Boltzmann equations.