有機發光二極體（Organic light emitting diode, OLED）具備高對比、可撓、自發光等優勢，已成為現今顯示器的主流；而在照明上，因具有面光源、面板輕薄的優勢，OLED也已打進照明市場；隨著許多研究團隊的努力，OLED近年來在效率與壽命上屢屢突破，然而效率的提升已達到瓶頸，其原因為OLED元件內部所放出的光線，大多會因元件內的全反射與各層薄膜的吸收而損耗，僅有約20%的光可以有效從發光層放出，因此，使用出光提取結構來提升OLED效率，就成為一個重要且有效的方法。
本研究探討內出光與外出光結構對OLED效能提升的影響，使用的暖白光元件結構為：ITO(陽極)、HATCN(電洞注入層)、TAPC(電洞傳輸層)、TCTA(電洞傳輸層)、EML (發光層)、BPhen(電子傳輸層)、LiF(電子注入層)與鋁(陰極)；外出光提取部分，透過在元件表面貼附外出光膜來增進光取出，結果顯示，在100 cd/m2下，無出光膜之元件能量效率為67.1 lm/W、外部量子效率為17.9%，而使用出光膜之元件，在同亮度下，能量效率為93.7 lm/W、外部量子效率為24.6%，能量效率與外部量子效率的增益分別為39.6%與37.4%；此效率之提升可歸因於：(1) 外出光膜粗糙的表面，使得大於臨界角度的光得以從元件內放出、(2) 出光膜的折射率介於空氣與玻璃基板之間，使得發生全反射的臨界角度增加，進而使更多光得以從玻璃取出。
在內出光提取部分，本研究所使用之內出光基板，在玻璃與ITO間置入散射層來增加光耦合率，且所使用之內出光基板，在濺鍍ITO前未對散射層施行平坦化處理，故基板具有89nm的平均粗糙度(Average roughness, Ra)；以此基板製作之元件，在1,000cd/m2時，能量效率為3.2 lm/W、外部量子效率為1.7%，且元件有局部短路的情形；因此，使用PEDOT:PSS（poly-(3,4-ethylene-dioxythiophene)-poly-(styrene-sulfonate)）取代HATCN作為電洞注入層，所製作之元件，在相同亮度下，能量效率提升至15.4lm/W、外部量子效率提升至9.4%，此效率的提升，可歸因於所塗覆的PEDOT:PSS填補部分凹洞，讓粗糙度由89nm降低至63nm，減少元件短路與漏電流的機會；但PEDOT:PSS仍無法有效填平表面坑洞，63nm的粗糙度對於OLED仍相當鉅大，故要以此內出光基板製作OLED，需找到一有效之平滑層，才能有效發揮功效。

Organic light-emitting diode(OLED) has the advantages of high contrast, flexible, self-luminous, etc. Because of the above advantages, OLED have become the mainstream of today's display market. In terms of solid state lighting market, due to the advantage of its flat light source and thin lighting panels, OLED has also penetrated the lighting market. With the efforts of research teams all over the world, OLED has made breakthroughs in both efficiency and lifetime in recent years. However, the improvement in efficiency has reached a bottleneck. The reason is that the light emitted from the OLED device is mostly lost to the total reflection and the absorption of each layer of film, and only about 20% of the light can be effectively emitted from the emissive layer. Therefore, using the light extraction structure to improve the efficiency of the OLED becomes an important and effective method.
This study explores the effect of internal and external light structures on the performance of OLED. The studied warm white OLED consist of ITO (anode), HATCN (hole injection layer), TAPC (hole transmission layer), TCTA (hole transmission Layer), EML (light emitting layer), BPhen (electron transport layer), LiF (electron injection layer) and aluminum (cathode).In the external light extraction part, the light extraction is enhanced by attaching the light extraction film on the surface of the device. The results show that at 100 cd/m2, the power efficiency of the device without the light extraction film is 67.1 lm/W and the external quantum efficiency is 17.9%. Then, the device using the light-extraction film has a power efficiency of 93.7 lm/W and external quantum efficiency of 24.6% at the same brightness, which have the enhancement of 39.6% and 37.4% for power efficiency and external quantum efficiency, respectively. Increment in efficiency can be attributed to: (1) the rough surface of the light extraction film allows light, which larger than the critical angle to be emitted from the device, and (2) the refractive index of the light extraction film is between air and the glass substrate, making the critical angle of total reflection increased, which allows more light to be taken out of the glass.
In the internal light extraction part, the internal light extraction substrate, which add a scattering layer between the glass and ITO is been used to increase light outcoupling. And, the light extraction substrate used in this study did not perform a planarization treatment on the scattering layer before sputtering ITO, so the substrate has the average roughness (Ra) of 89 nm. The device fabricated on this substrate has an power efficiency of 3.2 lm/W and an external quantum efficiency of 1.7% at 1,000 cd/m2, and the device has a partial short circuit. Therefore, we use PEDOT:PSS (poly-(3,4-ethylene-dioxythiophene)-poly-(styrene-sulfonate)) to replace HATCN as the hole injection layer, showing the power efficiency is increased to 15.4lm/W and the external quantum efficiency is increased to 9.4%. The increment of efficiency can be attributed to the fact that the coated PEDOT:PSS fills some of the holes, making the roughness decrease from 89nm to 63nm, which reduces the chance of short-circuit and leakage current of device. However, spin coating PEDOT:PSS is still unable to effectively smooth the surface. The roughness of 63nm is still very large for OLED. From the above mention, to make OLEDs with this kind of substrate, an effective planarization layer needs to be found in order to make its role.

目錄

摘要 I
Abstract III
致謝 V
目錄 IX
表目錄 XIII
圖目錄 XIV
壹、緒論 1
貳、簡介 3
2-1 有機發光二極體的基本結構 3
2-2、OLED的發光原理 4
2-3、OLED的能量傳遞機制 9
2-4、OLED的元件效率 12
2-5、OLED材料 14
2-5-1、陽極材料 14
2-5-2、電洞注入材料 14
2-5-3、電洞傳輸材料 15
2-5-4、電子傳輸材料 15
2-5-5、電子注入材料 16
2-5-6、陰極材料 16
參、出光提取技術的發展 17
3-1、有機發光二極體的光損失機制 17
3-1-1、光波導模態 17
3-1-2、基板模態 17
3-1-3、表面電漿子模態 18
3-1-4、輻射模態 18
3-2、外出光提取技術 19
3-3、內出光提取技術 26
肆、實驗方法 32
4-1、本研究使用之材料 32
4-2、元件設計與製備 34
4-2-1、元件電路設計 34
4-2-2、基板清潔 35
4-2-4、旋轉塗佈平滑層 36
4-2-5、發光層之製備 37
4-2-6、蒸鍍裝置 37
4-2-7、蒸鍍速率之測定 38
4-2-8、無機層之製備 38
4-2-9、出光膜的使用 39
4-3、元件光電特性量測 39
4-3、表面粗糙度量測 41
伍、結果與討論 42
5-1、外出光提取 42
5-1-1、元件結構 42
5-1-2、外出光提取對元件效率之影響 43
5-2、內出光提取 48
5-2-1、元件表現 48
5-2-2、旋塗PEDOT:PSS對基板粗糙度的影響 51
5-2-3、基板粗糙度對元件特性的影響 51
陸、結論 60
柒、參考文獻 62
附錄、個人著作目錄 66
(A)期刊論文 66
(B)研討會論文 66
(C)獲獎紀錄 66

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