| 研究生: |
陳佑誠 Chen, Yu-Cheng |
|---|---|
| 論文名稱: |
使用金屬氟化物緩衝層改善有機發光二極體光電特性之研究 The investigation on the optical and electrical characteristics of OLEDS using metal fluoride buffer layer |
| 指導教授: |
朱聖緣
Chu, Sheng-Yuan |
| 學位類別: |
碩士 Master |
| 系所名稱: |
工學院 - 奈米科技暨微系統工程研究所 Institute of Nanotechnology and Microsystems Engineering |
| 論文出版年: | 2008 |
| 畢業學年度: | 96 |
| 語文別: | 中文 |
| 論文頁數: | 94 |
| 中文關鍵詞: | 緩衝層 、有機發光二極體 |
| 外文關鍵詞: | buffer layer, OLED |
| 相關次數: | 點閱:111 下載:2 |
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本研究主要為製作高效率機發光二極體元件。由於緩衝層可以藉由如界面偶極的效應,降低ITO 與有機材料之間的能障,並且可改善表面附著不平整的問題,使得電洞注入效能提升;藉此讓更多的電洞、電子在有機發光層能產生再結合放光的現象,進而達到降低元件的驅動電壓、提升元件效率和發光強度等優點。在此研究我們採用NaF、AgF、CuF2 薄膜當作緩衝層製作高效率元件。
論文主要分為兩大部分,第一部份為研究各類金屬氟化物(NaF、AgF、CuF2)不同厚度以及不同表面處理對元件特性的影響。第二部份為探討單層薄膜的各種特性:穿透度以及吸收率、單電洞元件的電特性、功函數之量測、薄膜表面特性之量測等用以研究探討其電荷注入和傳輸機制以及對元件特性影響之原因。
由實驗結果發現:HOMO 值位於ITO 電極費米能階和NPB的HOMO值的NaF 可以改善電洞注入效率;AgF 與CuF2則因為可於表面形成一層極薄的金屬氧化物,其功函數高於NPB 的HOMO 值,亦可有效降低元件的驅動電壓以及增進其效率。
In this thesis, we focused on how to fabricate high efficiency organic light emitting diodes with high efficiency by inserting the buffer layer. It can make use of the effect like interfacial dipole to lower the energy barrier between the ITO electrode and the organic material and also improve the interface roughness between them. Thus it helps to increase the hole-injection efficiency. With it, more holes and electrons recombine and emit photons in the organic emission layer and achieve the goals of lowering driving voltage、increasing efficiency and emission intensity of devices. In this study, we use NaF, AgF and CuF2 thin film as buffer layer to fabricate high efficiency organic light emitting diodes.
In the first part of this search, we deposited NaF,AgF and CuF2 thin film with different thickness and surface treatment as buffer layer to investigate the characteristics of the OLEDS. At the second part, We also analyzed the various properties of the single layer thin film such as transmittance, absorption, hole only device, work function and surface structure etc to studied the hole injection、transport mechanism and the effects on the characteristics of the devices.
In this study, we found that NaF’s HOMO between ITO’s EF and NPB’s HOMO, hole-injecting efficiency can be improved. Because of generating the ultra-thin metal oxide film above AgF and CuF2 film and their work function was higher than HOMO of NPB, undoubtedly they could lower the driving voltage and improved the efficiency of the devices.
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