Effect of carrier distribution on carrier cooling in GaAs/AlGaAs quantum wells

A quantitative study of the effect of carrier-carrier scattering on carrier distribution in two-dimensional systems is carried out by means of calculations using the dynamically screened Boltzmann equation. Photoexcited carrier relaxation processes in both n-type-doped and undoped quantum wells (QWs) are also studied by time-resolved photoluminescence measurements using an up-conversion technique with a high time resolution of approximately 120fs. By measuring the time evolution of the photoluminescence (PL) intensity, the scattering rate of electrons into the conduction band minimum is obtained directly. Our simulations and experimental results demonstrate that the presence of the cool distribution does affect the carrier-carrier scattering rates significantly.