以光子晶體結構提升氮化銦鎵/氮化鎵藍色發光二極體之效能

Improved efficiency for InGaN/GaN light-emitting diodes using Photonic crystal

簡唯泰(Wei-Tai Chien)

指導教授 ： 雷伯薰

國立虎尾科技大學/電機資訊學院/光電工程系光電與材料科技碩士班/碩士(2016年)

摘要

近年來藍色發光二極體已被廣泛應用於指示燈、白光照明系統、 平面顯示器和其他光電元件。然而氮化鎵的激子束縛能較低，導致光 強度無法有效地轉換，因此無法在低操作電流情況下產生高亮度的白 光二極體。為了解決這個問題，本篇論文中，研究對於氮化銦鎵/氮 化鎵發光二極體的出光層進行不同的表面處理以提升發光二極體的 萃取效率，使用排水法在氧化銦錫窗層，自組分布聚苯乙光子晶體微 球做阻隔層，以乾蝕刻方式做表面粗化處理，其中在氧化銦錫窗層形 成光子晶體微球之元件主要應用於傳統封裝。利用排水法成長光子晶 體奈米結構具有低成本製成速度快等優點；當入射光通過氧化銦錫表 面粗化層，可增加入射角的光量，減少高折射率產生的全反射現象， 提升元件的外部量子效率。最後我們將最佳化結構引入氮化銦鎵/氮 化鎵藍色發光二極體中進行光特性的量測並確認相關方式的可行性。 本論文中，以排水法自組裝聚苯乙烯奈米球具有不需要使用大 型或昂貴的儀器設備、簡易組裝有序的三維奈米球構造。然而以排水 法自組裝奈米球，其中奈米球濃度、排水速率及基板表面處理皆會影 響奈米球的排列，我們將做一系列的研究。接著，我們以 Opti-FDTD 軟體模擬氧化銦錫窗層做表面粗化於發光二極體上的發光效率。我們 實驗比較的條件有二個，間距大小、蝕刻深度的條件下做表面粗化處 理。實驗部分，先在發光二極體上組裝單層排列奈米球，並以氧氣電 漿清洗機通以氧氣，以控制奈米球的直徑、間距來控制乾蝕刻時的間 距大小，並當間距為 30nm~50nm 之間的時候模擬效果最好；當蝕刻 深度為氧化銦錫窗層的三分之一深度模擬效果最好，其發光效率可提升37%。

關鍵字

藍色發光二極體 ； 聚苯乙烯 ； 光子晶體 ； Opti-FDTD 軟體

並列摘要

In recent years, the blue light-emitting diodes have been widely used indicator, white light illumination system, flat panel displays and other optoelectronic components. However, gallium nitride exciton binding energy is low, resulting in light intensity can not be efficiently converted, and therefore can not produce high-brightness white light diode at low operating currents. To solve this problem, this paper, the researchers for the indium gallium nitride / gallium nitride light-emitting diode light layers of different surface treatments to improve the extraction efficiency of light-emitting diode, the use of the drainage method in indium tin oxide window layer, since the group distributed a photonic crystal polystyrene microspheres make the barrier layer to dry etching way to do surface roughening treatment in which indium tin oxide window layer of microspheres photonic crystal element is formed mainly used in traditional packaging. Growth by water displacement photonic crystal nanostructure has the advantage of low cost and fast made; when the incident light by roughening the surface of an indium tin oxide layer, increase the amount of the angle of incidence of light, reducing the total reflection phenomenon generated by a high refractive index, lifting elements the external quantum efficiency. Finally, we will optimize the

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amount of structure into indium gallium nitride / gallium nitride blue light emitting diodes in optical characteristic measurement and confirmation of the feasibility of the relevant way. In this thesis in order to drain the self-assembly method does not require the use of polystyrene nanospheres has a large or expensive equipment, simple assembly and orderly three-Wei Naimi ball structure. However, self-assembly method to drain NSs, which NSs concentration, drainage rate and substrate surface treatment will influence the NSs arrangement, we will do a series of studies. Next, we Opti-FDTD simulation software window layer made of indium tin oxide surface roughening in luminous efficiency of light-emitting diodes on. Our experiments compared two conditions, the size of the pitch, do the etching depth under a surface roughening treatment. Experimental part, assembled on the first light-emitting diode monolayer NSs, and oxygen through an oxygen plasma cleaning machine to control the ball nm diameter, pitch as to control the size of the dry etching, and when the spacing simulation results when preferably between 30nm ~ 50nm; when the etch depth of the window layer is indium tin oxide third best simulate depth, which can improve the luminous efficiency of 37%.

並列關鍵字

The blue light-emitting diodes ； Polystyrene ； Photonic crystals ； Opti-FDTD software

參考文獻

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參考文獻