Time-resolved observation of anti-Stokes photoluminescence at ordered Ga0.5In0.5P and GaAs interfaces

Efficient anti-Stokes photoluminescence (ASPL) has been observed in Ga0.5In0.5P and GaAs single heterostructures. PL of Ga0.5In0.P-5 was generated when photoexciting the Ga0.5In0.5P/GaAs interface above GaAs band gap. In the anti-Stokes process the first step is photogeneration of electron and hole pairs in GaAs. The excited carriers can be excited once again in the second excitation step by absorption of laser light or by energy transfer of recombination energy in GaAs. Time-resolved measurements show that the ASPL is described by two components: the rapid decay and the slower decay. The rapid decay profile in the ASPL was only observed in an ordered sample, which is caused by a direct laser excitation of localized bound states at the heterointerface. On the other hand, energy transfer of recombination energy in GaAs generates the slower decay profile of the ASPL. (C) 2000 Elsevier Science B.V. All rights reserved.