Simultaneous filling of InAs quantum dot states from the GaAs barrier under nonresonant excitation

The authors have performed time resolved photoluminescence measurements by upconversion technique on InAs quantum dots embedded in an In Ga As ∕ Ga As quantum well emitting at 1.3 μ m at room temperature. A detailed analysis of the photoluminescence transients as a function of the excitation density and for different detection energies between the quantum dot transitions and the GaAs absorption edge shows that the intradot relaxation is slower than the direct carrier capture from the barrier states through a continuum background relaxation.