Characterization of InAs quantum dots in strained InxGa1-xAs quantum wells

The properties of InAs quantum dots placed in a strained InGaAs quantum wel l are investigated. The structures are sown by solid-source molecular beam epitaxy on GaAs substrates and are characterized using photoluminescence an d atomic force microscopy. Emission wavelength rind the optical quality of the quantum dots vary with gl growth temperature and also depend on the pos ition of the dots in the well. A strong dependence of the dot properties on the capping conditions is established. A postgrowth anneal similar to a ty pical laser cladding growth results in a large photoluminescence (PL) blues hift and reduces the PL intensity by more than two orders of magnitude. It is shown that these dots-in-a-well structures have superior optical propert ies as compared to conventional InAs dots in a GaAs matrix, and their emiss ion wavelength can be tuned past the technologically important wavelength o f 1.3 mu m. (C) 2000 American Vacuum Society. [S0734-211X(00)02103-X].