ABSTRACTWe investigate experimentally and theoretically optical and electronic properties of In0.3Ga0.7As/GaAs quantum dot molecules (QDMs) formed by two layers of self-assembled, vertically stacked quantum dots (QDs). Structures with In0.3Ga0.7As/GaAs QD layers separated by a thin GaAs barrier were grown by solid source molecular beam epitaxy, and were characterized by time-integrated photoluminescence (PL). For the temperature-dependent PL measurements a He-flow optical cryostat was used to control the temperature between 4 and 300 K. The experimentally observed behavior is in good agreement with that expected from our eight-band k·p calculations. Optical and electronic properties of these QDMs are further compared with those of dots grown under conditions that did not promote vertical organization.
Heterogeneous confinement in laterally coupled InGaAs/GaAs quantum dot molecules under lateral electric fields
