https://scholars.lib.ntu.edu.tw/handle/123456789/80913
Title: | 彈性應變對自組式量子點光電特性之影響(1/3) | Authors: | 郭茂坤 | Keywords: | 自組式量子點;應變場;有限元素法;薛丁格方程式;Self-assembled quantum dot;Strain field;Finite element method;Schrödinger equation | Issue Date: | 31-Jul-2004 | Publisher: | 臺北市:國立臺灣大學應用力學研究所 | Abstract: | 半導體元件的光電特性決定於元件 的能帶結構,而量子點中磊晶層之應變 將造成半導體導電帶特徵能量的改變, 進而影響電子躍遷難易度。本年度計畫 以有限元素法分析砷化銦/砷化鎵自組式 量子點(InAs/GaAs self-assembled quantum dot; InAs/GaAs SAQD)因其晶格 不匹配所引致的應變場,並進而探討應 變場對導電帶的特徵能量與電子機率密 度函數分佈之影響。本研究以線彈性力 學與熱應力理論,配合有限元素法套裝 軟體—FEMLAB,估算量子點內的應變 分佈,再將應變效應加入薛丁格方程 式,同樣以有限元素法予以分析。本年 度計畫考慮材料之異向性並與簡化為等 向性材料的結果比較,發現二種分析方 法之下,特徵能量與低特徵能量之簡併 狀態皆受到應變的影響而提升;同時發 現特徵能量與電子機率密度函數分佈, 異向與等向分析的差異性不大。因此, 對於砷化銦、砷化鎵而言,可以做等向 性的簡化,以利於模擬的進行。 In this year’s project, the models based on linear elasticity and thermal stress theory are developed to evaluate the strain distribution in the InAs/GaAs selfassembled quantum dot. The lattice mismatch in heterostructures induces the strain field which caculated by finite element package—FEMLAB. The Schrödinger equation, including the straininduced potential is also solved by means of the finite element method. The solutions consist of the eigenenergy and the probability density function of the conduction band. We treat the models by two different approaches, anisotropic material analysis and isotropic material simplification. Our results show that the strain effects shift the eigenenergy and the degeneracy of low eigenenergy. When considering the eigenenergy and the corresponding probability density function, the differences between two methods are small. Therefore, it is suitable to treat InAs and GaAs as an isotropic material. |
URI: | http://ntur.lib.ntu.edu.tw//handle/246246/21712 | Other Identifiers: | 922212E002072 | Rights: | 國立臺灣大學應用力學研究所 |
Appears in Collections: | 應用力學研究所 |
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922212E002072.pdf | 1.48 MB | Adobe PDF | View/Open |
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