透過您的圖書館登入
IP:18.209.209.28
  • 學位論文

以鋁/鎳/金為陽極提昇上發光型有機發光二極體之效率

Using Al/Ni/Au as anode in top emission organic light emitting diode to improve the efficiency

若您是本文的作者,可授權文章由華藝線上圖書館中協助推廣。

摘要


本論文研究上發光型有機發光二極體(TEOLED)之製作,首先討論以Al 60nm/ Au 2nm為陽極,LiF 0.2 nm/ Al 2 nm/ Ag 15nm為陰極結構之TEOLED。在加入電洞注入層材料m-MTDATA後,搭配高反射率的Al及高功函數的Au,可降低陽極與有機層間的能障,使驅動電壓由10V下降至6V。當m-MTDATA厚度到達最佳厚度15nm,電子與電洞數量將達到平衡的狀態,並有最佳的注入效果,使元件之發光亮度與發光效率分別達到14460 cd/m2、6.3 cd/A。隨後在Al/Au陽極結構中,插入一層功函數及導電率均與Au較接近的Ni,使陽極具有高功函數,且可避免因Al、Au界面產生的介金屬化合物,造成Kirkendall孔洞現象,使Al、Au剝離,造成元件壽命下降。當加入2nm 的Ni,可提高陽極導電率並維持高功函數,使元件之發光亮度及效率得到提昇,分別為10370 cd/m2及6.9 cd/A,並可延長元件壽命。此外,改良Al/Ni/Au之陽極結構,使Ni/Au具有週期性,除了可提高以Al/Au為陽極之TEOLED壽命,並提高陽極導電率,使電洞更容易注入至有機材料,得到更好的發光特性。當Ni/Au之週期等於2時,元件有最高的電流注入,並在內部產生建設性干涉,使元件得到最佳的發光亮度2568 cd/m2及發光效率2.8 cd/A。最後,本論文率先使用AlN取代玻璃作為OLED之基板,由於AlN基板的良好散熱特性,熱傳導係數約200 W/m•K,較玻璃之1.38 W/m•K高非常多,使元件操作在高亮度、高電流密度下,可以有效將熱經由基板散逸掉,避免有機材料因元件內部產生的焦耳熱而結晶化。並以電漿增強化學氣相沉積(PECVD)沉積SiO2使AlN基板平坦化,避免尖端放電,減緩元件衰減速度,提高元件之操作壽命。元件最高可以承受27V的驅動電壓,發光特性則可達到最大發光亮度3661cd/m2與最高發光效率5.05cd/A。

關鍵字

無資料

並列摘要


The top emission organic light emitting diode (TEOLED) with multilayer electrodes were studied. First, we use Al 60nm/Au 2nm in the design of the anode structure, and the cathode with LiF 0.2nm/Al 2nm/Ag 15nm structure is composed of TEOLED. After adding the hole injection material m-MTDATA. Energy barrier between the anode and the organic layer decreases, the driving voltage dropped from 10V to 6V. When the m-MTDATA reaches the best thickness of 15nm, electronic and the hole quantity could be balanced, which could lead to the best injection effect, makes the luminance and the luminance efficiency achieved 6218 cd/m2, and 7.7 cd/A. Afterwards, in anode structure Al/Au, inserted Ni, whose work function and conductivity was closer to Au. Avoid the contact surface of Au and Al be weakened by the Kirkendall void strips. The optimum thicknesses of the Ni in each layer as 2nm, may enable the promotion of conductivity to obtain the best luminance property. Also, to match Al with Ni/Au that has periodic anode structure. When cycle of the Ni/Au was about 2, namely the anode structure is Al/Ni/Au/Ni/Au, has best luminance, and also the luminance efficiency. Finally, the paper takes the lead to use the AlN instead of glass as the substrate of OLED, because the AlN substrate has a good radiation feature, the thermal conductivity was approximately 200 W/m.K, compared with the glass of 1.38 W/m.K, is obviously higher. As a result, when the part is operating under a high luminance, and a high current density, it could still effectively reduce the heat with the substrate dissipation, avoiding the organic material’s crystallization, which could make the weaken faster, to be caused by the joule heat produced by the interior device. Also, using PECVD to deposit SiO2 could flat the AlN substrate and avoid the point discharge. Then, the device could withstand 27V of driving voltage, and the TEOLED could produce a maximum luminance of 3661 cd/m2 and a maximum luminance efficiency of 5.05 cd/A.

並列關鍵字

無資料

參考文獻


[31] C. W. Chen, P. Y. Hsieh, H. H. Chiang, C. L. Lin, H. M. Wu, and C. C. Wu, Appl. Phys. Lett. 83 5127 (2003).
[10] S. han, C. Huang, and Z. H. Lu, J. Appl. Phys. 97 093102 (2005).
[8] S. K. So, W. K. Choi, L. M. Leung, and K. Neyts, Appl. Phys. Lett. 74 1939 (1999).
[30] S. F. Hsu, C. C. Lee, A. T. Hu, and C. H. Chen, Current. Appl. Phys. 4 663 (2004).
[2] C. W. Tang and S. A. VanSlyke, Appl. Phys. Lett. 51 913 (1987).

延伸閱讀