Abstract
We present time-resolved measurements of the relaxation of photoexcited holes in n-doped GaAs and InP with 100 fs time resolution. The band-edge luminescence is predominantly controlled by the hole dynamics, when the optical excitation density is much lower than the doping density. Information on the electron-hole scattering and hole-phonon scattering rates is obtained by varying the doping density. Thermal equilibrium between hot holes and lattice is found to be established on a subpicosecond time scale.