2005-08-012024-05-18https://scholars.lib.ntu.edu.tw/handle/123456789/711139摘要：所謂量子點是指以厚度僅數奈米的幾種不同材料，形成具有量子化能量位階，且三維均受侷限之微結構。受到量子化能量位階的影響，電子將被量子點侷限於一個很小的尺度內（趨近於一「點」的尺度內），因此量子點可視為理想之零維度系統。同時，由於此種三維均受侷限之微結構，其所造成的量子能階非常類似於原子能階現象，因而量子點有時又稱為人造原子。 由於量子點具有極高的能態密度，因此電子及電洞在量子點內之再結合率高，同時量子效率也高；故量子點極適合做為發光之光源，因而在光電元件的應用上具有很大的潛力；例如：可用以增進光電元件效率、可應用於高速通訊元件、或可製成低電流即可啟動且又溫度穩定性高的雷射元件等。 量子點元件的發光功率，與量子點的密度有極大的關係；目前能較成功得到高密度量子點的方法，係利用變形磊晶技術（例如：SK模式）以成長自組式量子點。而自組式量子點內變形磊晶層之應變，將直接影響半導體導能帶與價電能帶的結構及分佈，進而影響量子點內部的及其鄰近之電子的特性以及元件的光電性質。同時，由於半導體本身的壓電效應，應變的存在也將影響量子點鄰近的局部電場。目前量估算子點元件中，彈性應變之準確度，在國際學術界間仍<br> Abstract: Quantum dot is a coherent inclusion in a semiconductor matrix with truly zero-dimensional electronic properties. It has attracted substantial recent attention due to the potential of having three-dimension confinement on carriers and excitations and having “atom-like” electronic states. Quantum dots resemble those of atoms in an electromagnetic cage, rendering possible fascinating novel devices. The efficiency of quantum dots is strong related to the density of quantum dots in the quantum dot array. Self-assembled quantum dots formed by strained epitaxy have shown promising result to have quantum dot array. However, the strain fields inside and in the neighborhood of self-assembled quantum dots strongly affect the electronic band structure and hence the optical-electronic properties of quantum dots. For the optical-electronic properties in Ⅲ-Ⅴsemiconductors, there are two predominated strain effects, namely, changes of the conduction and valence band levels and changes of local electric fields due to piezoelectric effects. The influence of these two strain effects will be investigated from the point of view of elastic deformation. In this three-year’s project, we propose to develop a theory as well as numerical models to analyze the influence of elastic strains on optical-electronic properties of self-assembled quantum dots. The proposed works are as the following: 1. Evaluate and establish both mathematical theory and numerical models to simulate the elastic strain fields of self-assembled quantum dots; 2. Establish mathematical modeling on estimating the electronic band structure under the influence of elastic deformation; 3. Establish mathematical theory as well as numerical models to explore the influence of strain on optical-electronic properties; 4. Compare the numerical results against the existing experimental data; 5. Re-do all the investigation on quantum dot array.自組式量子點變形磊晶電子能帶結構奈米材料力學有限元素分析Self-assembled quantum dotStrained epitaxyElectronic band structureMechanics of nanomaterialsFinite element analysis