高分子有機發光二極體的發展常受限於材料的因素，高效率的材料通常為材料商所壟斷，價格也較為昂貴，因此始終無法普及。本論文的研究目標是希望利用一般較為普及的材料(PFO)製作出高效率的藍光發光二極體，而有了高效率藍光，則可利用摻雜的方式達到兩波段或是三波段白光，以應用在背光板或是照明上。而溶液製程的有機高分子發光二極體具有成本與簡化製程等優勢，但是由於高分子材料溶解性很好，製作多層結構時會有嚴重的互溶問題，這是重要瓶頸，而本實驗室一直以來發展的緩衝層可以解決這個問題，能夠有效達成多層元件的目標。
本論文的研究一開始先對材料特性作基本的特性研究，再針對缺陷加以改進，並尋求較高分子量的材料來解決穩定性不足的問題。最後利用緩衝層技術達成多層元件結構的設計，導入電洞傳輸層，以及電子傳輸層，將發光層夾在中間，遠離電極，並且進一步將緩衝層技術能穩定的適用在不同材料上。
實驗結果中，可以將普及的藍光高分子發光二極體電流效率由原先的0.8Cd/A提升到3.8Cd/A，亮度可以到8000Cd/m2，外部量子效率有3.99%，已經相當接近理論極限5%，成功達到將一般的材料做到跟高效率材料一樣好的目標。在確定了普及的材料同樣能夠具有高效率高亮度的表現後，我們開始就元件的壽命作研究，希望能達到商業應用的價值，這部分的研究還在持續進行中。

The development of polymer light-emitting diodes (PLEDs) was limited by the materials. The less material merchants controlled the high efficiency polymer and it is difficult to purchase and the price is also too high to be broad around. We want to use conventional polymer (PFO) to achieve the high efficiency blue light-emitting diodes in this studies. If we did the higher efficiency blue PLED, we could use the blending system to achieve the white light. And the application is including lighting, display and backlight for LCD. There are many advantages, like low price, simple fabricating and easy to large-area in solution process. But it is still a big problem of its layer mixing at the interface. We invented a buffer-liquid technique to fabricate multi-layer devices in our laboratory. This could enhance the device performance and prevent the layer mixing.
First, we did the basic experiments to realize the characters of the materials. Then we focused on solving the defects affected by the moisture and oxygen, and searched for high molecular-weight polymers. Finally, we used buffer-liquid technique to fabricate multi-layers structure, including hole-transport layer and electron-transport layer. And we made more stable devices of different materials by using this new method.
The efficiency increased form 0.8 cd/A to 3.8 cd/A. We could achieve the luminance of 8000 Cd/m2 and the external quantum efficiency of 3.99%, which is close to the maxima value. We fabricated the high efficiency LED by conventional materials compared to the materials difficult to get. Then we want to improve the lifetime of the PLEDs. And it is still continuing.

[1].M. Pope， H.P. Kallmann， P. Magnante， J. Chem. Phys. 38 (1963) 2042.
[2].C.W. Tang， S.A. VanSlyke， Appl. Phys. Lett. 51 (1987) 913.
[3].J.H. Burroughes， D.D.C. Bradley， A.R. Brown， R.N. Marks， K. Mackey， R.H. Friend， P.L. Burn， A.B. Holmes， Nature 347 (1990) 539.
[4].S. R. Tseng, S. C. Lin, H. F. Meng, Appl. Phys. Lett. 88, 163501(2006)
[5].D. A. Skoog, D. M. West, F. J. Holler,“Fundamentals of analytical chemistry”,5th edition , Saunders College Publishing(1998)
[6].M. A. Lambert and P. Mark， ”Current Injection in Solids”， New York: Academic， 1970.
[7].J. Frenkel, Phys Rev. Letts., 14, 229 (1965)
[8].U. Wolf, V. I. Arkhipov, H. Bassler, Phys. Rev. B, 59 7507 (1999)
[9].S.R. Forrest, D. D. C. Bradley, M.E. Thompson, Adv. Mater., 15, 1043 (2003)
[10].J. S. Kim, R. H. Friend, and F. Caciallia) APPLIED PHYSICS LETTERS VOLUME 74, NUMBER 21
[11].X. M. Ding L. M. Hung, L. F. Cheng, Z. B. Deng, X. Y. Hou, C. S. Lee,a) and S. T. LeeAPPLIED PHYSICS LETTERS VOLUME 76, NUMBER 19
[12].Beeling Low, Furong Zhu,a) Keran Zhang, and Soojin Chua APPLIED PHYSICS LETTERS VOLUME 80, NUMBER 24
[13].J. S. Kim, P. K. H. Ho, C. E. Murphy, et al, Macromolecules 37, 2861 (2004)
[14].D. D. C. Bradley, M. Grell, X. Long H. Mellor, and A. Grice, Proc. SPIE 3145, 254 1998.
[15].E. J. W. List, R. Guentner, P. S. D. Freitas, and U. Scherf, Adv. Mater. 14, 374 2002.
[16].Y. Sato, T. Ogata, S. Ichinosawa, Y. Murata, Synth. Met., 91, 103 (1997)