Quantum Confinement in Elliptical Graphene Quantum Dots

<b>Alloy graphene quantum dots (QGDs) are nanostructures that have the unique properties of high conductivity, high mechanical flexibility, chemical stability, and tunable emission wavelengths. Materials with these properties are highly sought after in the energy industry for the enhancement of optics, photonics, and solar cells. To effectively apply QGDs to this technology, it’s necessary to understand how changing the dimensions of the dots will affect the electron confinement energies, and by extension, the emission wavelengths of the dot. Using the multiphysics software COMSOL and the finite element method, computational models of elliptical SiGe GQDs were created to analyze confinement energies. The goal of the model was to determine the effects that elliptical eccentricity in SiGe GQDs had on confinement energies within the dot. In particular, the relationship between radii ratio of the ellipse, μ, and confinement energy was investigated. The results indicated a minimum confinement energy of 19.328 eV for a circular dot with μ = 1, and an increase in confinement energy as μ approaches 0. Specifically, the confinement energies as a function of μ were found to fall on a decreasing exponential curve. These measurements act as an important starting point for analyzing the quantum confinement effect in 2D QDs. In the future this model can be modified to investigate the confinement energies of other 2D QDs such as MoS₂, which can provide important insights into potential applications for these materials.</b>