Carrier dynamics in an InGaAs dots-in-a-well structure formed by atomic-layer epitaxy

Abstract

We investigated the effects of carrier dynamics on the temperature dependence of the photoluminescence (PL) of an InGaAs dots-in-a-well (DWELL) structure. The quantum dots (QDs) were formed by the atomic layer epitaxy (ALE) technique alternately supplying InAs and GaAs sources. It was found from the PL measurements at various temperatures that the DWELL structure was accomplished through the generation process of the intermediate layer between the quantum well (QW) and the QDs during the formation of the QDs inside a QW. The temperature dependence of the PL was fitted well with the thermal quenching equations on the basis of the rate equation model. The rate equations can be explained by the carrier dynamics, which included in the radiative recombination, the carrier thermal escape and the carrier capture process occurring in these three layers, i.e., QW, QD, and the intermediate layer.