English  |  正體中文  |  简体中文  |  Items with full text/Total items : 13611/18791
Visitors : 11887432      Online Users : 225
RC Version 3.2 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
Scope Adv. Search
LoginUploadHelpAboutAdminister

Please use this identifier to cite or link to this item: http://ir.ncue.edu.tw/ir/handle/987654321/544

Title: 氮化銦鎵藍光發光二極體極化效應之研究
Other Titles: Investigation of Polarization-Related Effect on Blue InGaN Light-Emitting Diodes
Authors: 蔡妙嬋
Contributors: 郭艷光
Yen-Kuang Kuo
蔡妙嬋
Miao-Chan Tsai
Keywords: 發光二極體;壓電效應;氮化銦鎵
light-emitting diodes;piezoelectric effect;InGaN
Date: 2008
Issue Date: 2010-10-18T07:22:10Z
Description: 碩士
光電科技研究所
Abstract: 極化效應強烈地影響了氮化物發光二極體之光電特性。在各磊晶層之介面間累積的極化電荷使元件產生強大的內建極化電場,因而影響了發光二極體的能帶結構,特別是在量子井中,極化效應使量子井之能帶傾斜,電子與電洞分別侷限於井的兩側,大幅降低載子結合發光的機會,因此限制了發光二極體的發光功率及效率。截至目前為止,已有相當多的研究團體致力於探討如何降低氮化物之極化電場以提升光電半導體元件的性能。本論文將從模擬的觀點研究極化效應對氮化銦鎵藍光發光二極體之影響,並提出可改善極化效應的發光二極體結構設計。
在本論文的第一章中,針對氮化物材料之極化效應議題做一介紹,包括極化效應相關原理、計算以及發展概況。
在第二章中介紹了本論文研究所參考的氮化銦鎵藍光發光二極體結構,並介紹在模擬程式中與氮化物相關之物理參數設定。
第三章分別探討氮化銦鎵藍光發光二極體受總極化、自發極化以及壓電極化效應的影響,包括了對發光性能、能帶結構、極化電場、載子分佈以及輻射再結合速率…等之特性分析,並找出主宰氮化銦鎵藍光發光二極體發光特性之極化效應。
第四章探討使用四元氮化鋁鎵銦做為藍光發光二極體之電子阻礙層與井障對元件特性的影響。計算出與原始參考結構之氮化銦鎵量子井極化電荷匹配的氮化鋁鎵銦井障,以及與氮化鎵極化匹配的氮化鋁鎵銦電子阻礙層,欲利用其抑制元件的極化效應,使量子井內的能帶達到平坦,提升電子與電洞波函數在空間上的重疊率,增加電子電洞對結合速率,以達到發光二極體發光功率的提升。
第五章探討將氮化銦鎵量子井設計為步階函數狀對藍光發光二極體之特性影響,找出藍光氮化銦鎵發光二極體最佳步階函數狀量子井結構,並深入分析致使步階函數狀量子井發光二極體發光效率改善之物理原因。
最後在第六章為本論文做一個完整的結論。
The polarization effect is an essential characteristic for the III-nitride materials. The existence of the strong electrostatic fields、which are generated by the spontaneous and piezoelectric polarizations、has a significant influence on the band profile、especially in quantum well region、and also results in quantum confined Stark effect and poor electron-hole overlap. Consequently、the radiative recombination rate、internal quantum efficiency、and optical performance of the light-emitting diodes are limited. Several research groups have focused on how the electrostatic fields might be removed and how the band bending situation might be improved. In this thesis、the effect of polarization on the blue InGaN light-emitting diodes has been numerically investigated. In addition、the appropriate design of the structure is proposed to enhance the optical characteristics of the light-emitting diodes.
In chapter 1、the literatures and papers related to the concept of polarization-related effect are introduced and the calculation method of polarization charges is also described.
In chapter 2、the structure of the blue light-emitting diode under study and the physical parameters used in APSYS simulation program are introduced.
In chapter 3、the effect of spontaneous and piezoelectric polarizations on optical characteristics of the blue InGaN light-emitting diode is investigated. The band diagrams、overlap between electron and hole wavefunctions、electrostatic fields、distribution of electron and hole carriers、and radiative recombination rate are analyzed and compared.
In chapter 4、for the blue InGaN light-emitting diodes、the quaternary AlGaInN polarization-matched electron-blocking layer and barrier layers are utilized to reduce the polarization effect. Furthermore、the optimization of the optical performance is attempted by using proper AlGaInN epitaxial layer.
In chapter 5、the effect of the staggered quantum well upon the blue InGaN light-emitting diodes is numerically studied. Moreover、the optimized staggered quantum well structure is demonstrated、and the physical origins for the improvement in optical performance are figured out.
Finally、a summary to the previous studies is provided in chapter 6.
Appears in Collections:[光電科技研究所] 博碩士論文

Files in This Item:

File SizeFormat
index.html0KbHTML425View/Open


All items in NCUEIR are protected by copyright, with all rights reserved.

 


DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - Feedback