Exciton thermal escape in symmetric InAs quantum dots in InGaAs/GaAs well structures
Tóm tắt
The photoluminescence and its temperature dependence have been investigated for the ensembles of InAs quantum dots embedded in symmetric In0.15Ga0.85As/GaAs quantum wells with different PL intensities. The solution of the set of rate equations for exciton dynamics was used to analyze the nature of thermal activation energies of the QD photoluminescence quenching. It is revealed two different stages of thermally activated quenching of the QD PL intensity caused by thermal escape of excitons from the In0.15Ga0.85As/GaAs QW into the GaAs barrier and from the QDs into the QWs with their subsequent nonradiative recombination. The variety of activation energies of PL thermal quenching is discussed as well. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Từ khóa
Tài liệu tham khảo
D.Bimberg M.Grundman andN. N.Ledentsov Quantum Dot Heterostructures (Wiley & Sons 2001) p. 328.
T. V.Torchynska J. L.Casas Espinola S.Ostapenko M.Dybiec O.Polupan L. V.Borkovska N. O.Korsunska A.Stintz P. G.Eliseev andK. J.Malloy Phys. Rev. B (2006) to be published.