請用此 Handle URI 來引用此文件:
http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/21369
標題: | 利用蝕刻孔洞法研究圖案化藍寶石基板上近紫外光
發光二極體的內部量子效率 Investigation of internal quantum efficiency in near-ultraviolet light-emitting diodes on patterned-sapphire substrates by the etch-pits method |
作者: | Chen-Kai Yi 易振楷 |
指導教授: | 管傑雄(Chieh-Hsiung Kuan) |
關鍵字: | 內部量子效率,氮化鎵,圖案化藍寶石基板,蝕刻孔洞法,近紫外光發光二極體, Internal quantum efficiency,gallium nitride,patterned sapphire substrate,etched pits density,near-ultraviolet light-emitting diode, |
出版年 : | 2019 |
學位: | 碩士 |
摘要: | 內部量子效率(IQE)的提升對於近紫外光發光二極體(NUV-LED)之發光效率影響極為重要。目前之NUV-LED主動層材料為氮化鋁鎵,其IQE對於穿隧差排密度之敏感度較高。而其中材料晶體品質直接影響元件的內部量子效率(IQE),因此對於材料晶體品質的分析與增進變得十分重要。
在本篇論文中,我們首先改善了用於分析晶體品質的蝕刻孔洞法(EPD),使之能確切地計算出穿隧差排密度(TDD),並實際應用於分析近紫外光發光二極體(NUV-LED)之緩衝層(Buffer layer)氮化鎵薄膜之缺陷密度。本研究利用圖案化藍寶石基板技術來提升磊晶晶體品質,在優化後的蝕刻孔洞法分析下,我們發現螺旋形差排與混和型差排密度,由2.09*106成功的減少至1.66*106 (cm-2),整體減少了20.5%的缺陷密度。 該結果最終與鄭文逸同學的拉曼分析模型互相印證,成功證明利用圖案化藍寶石基板(Patterned Sapphire Substrates, PSSs) 可以大幅減少氮化鎵薄膜的穿隧差排密度(Threading Dislocation Density)以增加發光二極體主動層之磊晶品質。 The improvement of internal quantum efficiency (IQE) is significant for the luminous efficiency of near-ultraviolet light-emitting diodes (NUV-LEDs). Recently, the active layer material of NUV-LEDs is AlGaN, whose IQE is highly sensitive to the threading dislocation density. Since the IQE is strongly affected by the crystal quality, it is very important to improve and analyze the crystal quality of materials In this thesis, we first modified the etch pits density (EPD) method for crystal quality analyzation, which made the calculation of the threading dislocation density (TDD) more precise. The method then directly applied to analyze the defect density of the NUV-LEDs buffer layer. In this study, we improve the crystal quality with pattern sapphire substrates, and analyze its crystal quality with the modified EPD method. The results show that the screw and mixed type dislocation density were successfully decreased from 2.09*106 to 1.66*106 (cm-2), totally 20.5% reduced. Finally, the results have compared to the investigation through Raman spectrum analyzation, which is executed by Wen-yi Zheng. The decrease of threading dislocation density of NUV-LEDs buffer layer with PSSs is cross-confirmed successfully. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/21369 |
DOI: | 10.6342/NTU201903041 |
全文授權: | 未授權 |
顯示於系所單位: | 電子工程學研究所 |
文件中的檔案:
檔案 | 大小 | 格式 | |
---|---|---|---|
ntu-108-1.pdf 目前未授權公開取用 | 2.55 MB | Adobe PDF |
系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。