Optical properties of submonolayer depositedInGaAs/GaAs quantum dots

摘要

Optical properties of InGaAs/GaAs quantum-dot-quantum-well(QDQW) heterostructures are investigated by low-temperature selectivephotoluminescence (PL) and time-resolved PL. In our QDQW structure,InGaAs QDs are formed by vertical correlation of nanoscalesubmonolayer deposited InAs islands in a GaAs matrix, and surroundedlaterally by a quantum-well layer formed by In-Ga intermixing. Differentlocal phonon modes, from the InGaAs QW, the InGaAs QDs, theinterfaces and the GaAs barrier are observed in the resonantly excited PLpeaks. The PL rise time (31 ps) and the PL lifetime(1276 ps) of the QDstate are comparable with those of typical Stranski-Krastnow QDs.