近年來，有機發光二極體 (Organic Light Emitting Diode，簡稱OLED) 在顯示器與電子產品應用上蓬勃發展，目前技術上已發展成熟，但在OLED製程中，折射率不匹配是一個常見的問題，也被稱為折射率缺陷。它指的是OLED中使用的不同材料之間的折射率差異，導致光在不同材料之間的界面上產生反射和折射。這些反射和折射造成了光的能量損失和光路徑的改變，最終影響了OLED的光學性能。而微透鏡陣列 (Microlens Array，簡稱MLA) ，透過調節折射率、結構厚度、界面修飾以及尺寸等光學層面的優化，來改善OLED的光學損失，進一步提升光耦合效率。
本論文分成兩部分探討如何製作微透鏡陣列以及應用上OLED上之效果。第一部分，我們討論選擇三氧化鎢 (WO3) 與氟化鎂 (MgF2) 作為折射率匹配層(Refractive Index Matching Layer，簡稱RIML) ，盡管MgF2具有較玻璃低的折射率，但其難以被雷射加工，因此我們將WO3放置底層作為雷射吸收層，並將MgF2堆疊在WO3上，此結構能夠成功降低MgF2的加工難度，使其易於圖案化。
在第二部分，我們將WO3/ MgF2加工成一系列尺寸不同的MLA，並應用在綠色磷光OLED上，其單層式折射率匹配層結構最佳效率提升率為18.88%，後續我們優化出MLA之最佳面積與厚度，其最佳效率提升率為32.46%，兩者相比之下，新增圖案化陣列其OLED效率提升率額外增加13.58%，使其最大外部量子效率達到24.57%。

In recent years, Organic Light Emitting Diodes (OLEDs) have experienced a flourishing development in applications such as displays and electronic devices. The technology has now reached a mature stage. However, in the OLED fabrication process, refractive index mismatch is a common issue, also known as refractive index defect. This refers to the difference in refractive indices between different materials used in OLEDs, which results in reflection and refraction of light at the interfaces between these materials. These reflections and refractions result in energy loss and alteration of the optical pathway, ultimately affecting the optical performance of OLEDs. Microlens Array (MLA) offer a solution to mitigate these issues by optimizing optical aspects such as refractive index, structural thickness, interface modification, and size. By enhancing these optical parameters, MLA help to improve the optical losses and enhance the efficiency of light coupling in OLEDs.
This paper is divided into two parts, discussing the fabrication of a microlens array and its application in OLEDs. In the first part, we explore the use of tungsten trioxide (WO3) and magnesium fluoride (MgF2) as the refractive index matching layer (RIML). Although MgF2 has a lower refractive index than glass, it is difficult to process using lasers. Therefore, we place WO3 as the bottom layer to act as a laser-absorbing layer and stack MgF2 on top of WO3. This structure successfully reduces the processing difficulty of MgF2 and enables its patternization.
In the second part, we fabricated a series of MLAs with varying sizes using WO3/ MgF2 and applied them to green phosphorescent OLEDs. The MLA with a single-layer refractive index matching structure achieved an optimal efficiency enhancement of 18.88%. Subsequently, we optimized the MLA for the best area and thickness, resulting in an optimal efficiency enhancement of 32.46%. In comparison, the addition of patternized arrays further increased the OLED efficiency enhancement by an additional 13.58%, leading to a maximum external quantum efficiency of 24.57%.

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