Suppression of the photoluminescence quenching effect in self-assembled InAs/GaAs quantum dots

We report results that witness the possibility of controlling the temperature (T) dependence of the photoluminescence (PL) from self-assembled InAs/GaAs quantum dots (QDs) overgrown by an InxGa1-xAs layer forming a quantum well. A growth treatment using tetrachloromethane eliminates the quenching of the PL intensity at room temperature. A reduction in the concentration of defects in the GaAs matrix and the corresponding increase of the radiative lifetime of the photocarriers are invoked to explain this effect. A simple model analyzing the behavior of the quasi-Fermi level in the QD heterostructure confirms our explanation. (c) 2005 American Institute of Physics.