Inter-valley phonon-assisted Auger recombination in InGaAs/InP quantum well

Nonradiative processes are studied in InGaAs/InP quantum wells (QWs) as a function of the pump power and the temperature, using time-resolved photoluminescence. Intravalley disorder induced direct and intervalley phonon-assisted indirect Auger processes are found to be responsible for nonradiative recombination in low mobility and high mobility quantum wells, respectively. Both Auger processes are spatially separated: the phonon-assisted and direct Auger recombinations take place in the central part of the QW and near the interfaces, respectively. The recombination rate corresponding to the phonon-assisted Auger process is shown to increase with the temperature, while no influence of the temperature was detected for the rate of the disorder induced direct Auger process. The presented data point to the X and/or L valleys as final states for the Auger electron in the intervalley Auger process. Moreover, Auger recombination associated with different confined levels is studied. We show that the conditions for the intervalley phonon-assisted Auger processes are fulfilled for the ground states of the confined electrons and holes, while the nonradiative recombination due to the excited states is dominated by the direct Auger process.