Home » Influence of barrier layer on optical and electronic properties of quantum dot molecules. by Prasoon Pancholi
Influence of barrier layer on optical and electronic properties of quantum dot molecules. Prasoon Pancholi

Influence of barrier layer on optical and electronic properties of quantum dot molecules.

Prasoon Pancholi

Published
ISBN : 9780549814016
NOOKstudy eTextbook
90 pages
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 About the Book 

In recent years, it was suggested that the performance of nanostructure-based optoelectronic devices, in particular quantum dot-based devices, may be enhanced when the active region of the device consists of dots that are coupled laterally and/orMoreIn recent years, it was suggested that the performance of nanostructure-based optoelectronic devices, in particular quantum dot-based devices, may be enhanced when the active region of the device consists of dots that are coupled laterally and/or vertically. The electronic coupling between the dots provides a new degree of freedom in engineering the electronic bandstructure of the nanostructures. For example, strong electronic coupling between two dots defines a new entity, known as a quantum dot molecule (QDM). We provide in this thesis a comparative theoretical and experimental study of structures consisting of two layers of vertically coupled InAs/GaAs QDs, grown by molecular beam epitaxy on (001) GaAs substrates, in which the GaAs barrier layer thickness was varied between 4 and 10 nm, thus insuring very strong coupling between the dot layers and the existence of molecule-like behavior.-Theoretically, to understand the nature of the electronic and optical properties of the self-assembled dots and molecules, we determined the strain distribution in the dots. The strain effects were included via the deformation potential theory in an eight-band k&dot-p model to calculate the respective electronic band structures. Our experimental investigations of the optical and structural properties of QDM structures confirm the formation of QDMs with energy splittings that agree well with the results of our calculations.