Model of photoluminescence of InAs quantum dots embedded in indirect band gap AlGaAs matrices

Photoluminescence kinetics in InAs quantum dots embedded in indirect-gap AlGaAs matrices has been studied. It has been found that the duration of the photoluminescence decay at low temperatures greatly decreases from milliseconds down to nanoseconds with decreasing the AlAs fraction in the AlGaAs matrix. The experimental results are interpreted in the framework of a model that takes into account an exchange splitting of excitonic levels in the quantum dots.