Structural Characteristics on InAs Quantum Dots multi-stacked on GaAs(100) Substrates

다국어 초록 (Multilingual Abstract)

The InAs self-assembled quantun dots (SAQDS) were grown on a GaAs(100) substrate using a molecular beam epitaxy (MBE) technique. The InAs QDs were multi-stacked to have various layer structures of 1, 3, 6, 10, 15 and 20 layers, where the thickness of the GaAs spacer and InAs QD layer were 20 monolayers (MLs) and 2 MLs, respectively. The nanostructured feature was characterized by photoluminescence (PL) and scanning transmission electron microscopy (STEM). It was found that the highest PL intensity was obtained from the specimen with 6 stacking layers and the energy of the PL peak was split with increasing the number of stacking layers. The STEM investigation exhibited that the quantum dots in the 6 stacking layer structure were well aligned in vertical columns without any deflect generation, whereas the volcano-like deflects were formed vertically along the growth direction over 10 periods of InAs stacking layers.