| Summary: | 碩士 === 國立交通大學 === 電子物理系所 === 95 === In this thesis, I present a theoretical study of electron-hole exchange interaction in self-assembled quantum dots, a key element in the spin-characteristics polarized optical spectra and the spin dynamics of dots. We start with exploring the strain effects in self-assembled quantum dots on the spin structure of single exciton in dots. By taking the theory by J. H. Davies, we carry out the numerical calculation for the strain distribution in a box-like InAs/GaAs quantum dot and calculate the strain-modified effective potential profile for conduction electrons, heavy-holes, and light-holes, respectively. The hole carriers bounded in dots are confirmed to be heavy-hole-like. In the basis of pure heavy-hole exciton, we derive the generalized formulation of e-h exchange interaction in semiconductors, providing a base for the studies of the fine structure of excitons in a variety of nanostructures, from 3D confining nanocrystals to quasi-2D self-assembled quantum dots. At last, we apply the theory to InAs/GaAs self-assembled quantum dots and carry out the analysis of the polarized emission spectrum directly. According to the analysis, we can relate the polarized spectrum feature to the spin structure of excitons and dot geometry.
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