Fine Structure Splitting and Optical Properties of Single Neutral Excitons in Quantum Dot Light Sources

• Main Author: 林佩儀
• Other Authors: Cheng, Sun-Jen
• Format: Others
• Language: en_US
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/74681262596722375197

碩士 === 國立交通大學 === 電子物理系所 === 101 === This thesis theoretically studies the size effects of quantum dots (QDs) on the fine structure properties as well the optical polarization. Known as representative excellent quantum light sources, two semiconductor QDs, InAs/GaAs self-assembled QDs and hierarchical GaAs/AlGaAs QDs are considered. Excitonic structures of the QDs are computed numerically by combining the four-band Luttinger-Kohn k?況’s model for valence hole and single-band model for conduction electron within the 3D-parabolic potential model of QD. Optical polarizations of the single excitons in the dots are calculated by using Fermi’s Golden rule. Initial strain in InAs/GaAs self-assembled QDs induced by lattice mismatch is formulated as a function of size analytically and numerically calculated using finite-element software package, Comsol multiphysicsR. Analytical results indicate that the energetic competition of the size-dependent short- and long-ranged e-h exchange interactions diminish the fine structure splitting of an elongated QD. Moreover, the electronic structures and optical polarization properties of GaAs bulk under stress control were studied theoretically, in which the corresponding microscopic Bloch wave functions were visualized under applied stress by using the Slater Orbital model.