自組式量子點應變之理論研究

Abstract

本論文主要是探討砷化銦與砷化鎵(InAs/GaAs)自組式量子點(self-assembled quantum dots)的應變分佈。文章中除了利用古典連體力學(classical continuum mechanics)來推導格林函數(Green's function)及正逆傅立葉轉換(Fourier transforms)來計算自組式量子點的應變分佈外，也使用COMSOL(有限元素軟體)計算量子點的應變，並將這兩個方法的結果做比較。 由於應變效應會直接影響量子點電子電洞的侷限位能，所以，應變的分佈相當重要，因此，在本文一開始，介紹了應變分量所呈現之位移圖像。此外，我們計算多種形狀量子點包含量子盒與截角金字塔的應變與侷限位能，包含XY對稱與不對稱的情況，藉此了解不同形狀下侷限位能的改變。此外，我們也計算垂直耦合雙量子點的應變與侷限位能。

This thesis is mainly to explore the strain distribution of InAs/GaAs of self-assembled quantum dots. The article takes advantage of classical continuum mechanics to infer Green's function and Fourier transforms, calculating the strain distribution of self-assembled quantum dots. Also using COMSOL calculate the strain of quantum dots, and comparing the results of these two methods. Since the strain effect directly affects the confinement potential of electron and holes of quantum dots. Therefore, the strain distribution is essential. With this in mind, I start the article with the introduction of the displacement graphics of the strain component. In addition, a variety of shapes of quantum dot we calculate the strain and the confinement potential, including the XY symmetry and asymmetry, to understand the different changes in shape under the confinement potential. In addition, we calculate the strain and the confinement potential of the vertically coupled double quantum dots.