Picosecond carrier dynamics and studies of Auger recombination processes in indium arsenide at room temperature

Pump-probe midinfrared spectroscopic experiments with 10-ps resolution have been performed in ultrathin (0.09--3.3 {μ}m) undoped molecular-beam epitaxy InAs epilayers on GaAs substrates near and above the fundamental absorption edge (h{ν}=0.335--0.485 eV). Significant bleaching due to a dynamic Moss-Burstein effect was seen near the excitation photon frequency. Bleaching recovery times in the range 3000--35 ps were found, and were strongly dependent on the pump photon energy, InAs epilayer thickness, and irradiation dose in the case of layers implanted with high-energy protons. The measured evolution of the excess carrier distributions as a function of delay after excitation allowed the coefficient for Auger recombination in InAs to be measured as 1.1±{}0.1×{}10^-26 cm⁶ s^-1. The carrier recombination rates were found to be governed by the Auger effect for ``thick'' (>0.5 {μ}m) samples and by a recombination velocity of {}2.7×{}10⁴ cm s^-1 at the dislocated InAs/GaAs heterointerface for ``thin'' (0.5 {μ}m) samples.