AUGER HEATING OF CARRIERS IN GAAS ALAS HETEROSTRUCTURES/

The photoluminescence of GaAs/AlAs multiple quantum wells structures u nder optical ps excitation is investigated for carrier densities in th e range 10(18)-4 x 10(19) cm(-3) with frequency and time-resolved spec troscopic techniques. The measurements give a direct evidence of the o ccurrence in the sample of carrier heating. This energy up-conversion gives rise to photoluminescence from the states near the Fermi level w hose intensity and time evolution depend on the carrier density in a s trongly non-linear way. The observed behaviour can be explained introd ucing in the carrier dynamics an up-conversion mechanism due to Auger- like processes. (C) 1997 Elsevier Science Ltd.