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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
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
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。
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

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