自1987年起多層有機發光二極體被Tang 及 Vanslyke 兩人所論證出來後，有機發光二極體便吸引眾人之目光，不外乎有許多的優點，像高對比度、低應答時間、自發光、高亮度、視角廣、厚度薄、應用在全彩化上等等，因為有這麼多的優點，使得有機發光二極體在次世代的平面顯示器上佔有極大的應用。
　　然而在眾多光色中，以白光最為重要，因為白光可用來當做液晶顯示器的背光源或應用在全彩化的技術上，所以白光有機發光二極體對整個顯示器的發展其為重要；但是多層結構有機發光二極體有個很大的問題，就是色度座標會隨偏壓的不同而有所改變。因此，本實驗之目的即在研發單層的白光二極體，得以改善色度因偏壓的不同而有改變的現象。
　　此實驗所使用的主要材料有NPB、DPVBi、Rubrene、BCP、Alq3 及 Al；NPB在此當作電動傳輸層、DPVBi為藍色發光材料及host材料、Rubrene為橘色材料、BCP為電洞阻擋層、Alq3為電子傳輸層。本實驗之重點在於找到DPVBi：Rubrene之共蒸著鍍率比例，以及藉由改變Rubrene在DPVBi的摻雜位置來討論其發光特性。鍍率比例的不同會影響到能量轉換的效率，而此實驗就是藉由不完全的能量轉移來達到混光的效果。一開始從實驗的結果得知共蒸著鍍率比例為1:0.05可以得到不完全的能量轉移，鍍率比例大於1：0.05發的是純橘光，鍍率小於此比例的話，是有藍色的光產生。此時各個材料理想厚度為NPB(200Å)、DPVBi：Rubrene(250Å)、BCP(50Å)、Alq3(200Å)。之後再把DPVBi分為兩部分，一部分有摻雜，一部分沒摻雜，進而改變兩部分的位置來探討其發光效果。在此實驗中，我們得到NPB / DPVBi：Rubrene / DPVBi / BCP / Alq3 / Al 為最佳的結構。
　　之後再調整共蒸著鍍率比例，我們得到最佳的鍍率比例為1：0.006。在最佳之結構下所量測到的CIE座標為(0.31 , 0.35)，在11V之偏壓下所得到的近似白光之輝度可達到3833 cd/m2。

　Since multilayer organic light-emitting diode had been demonstrated by Tang and Vanslyke in 1987, organic light-emitting diode has received much attention due to its many advantages, such as high contrast, fast response, self emitting, high brightness, wide view angle, thin form factor, and supports in full color application, etc. Because of these advantages, organic light-emitting diode has great application in flat-panel display of next generation.
　However, among many colors of light source, white light is the most important of all because it can be backlight for liquid crystal displays or apply to full color technology. As a result, white organic light-emitting diode plays an important role The critical problem of the multilayer organic light-emitting diode is that the CIE coordinate will change with the different bias voltage. Therefore, the purpose of this experiment is to fabricate a white organic light-emitting diode with single-layer, in order to improve the problem of changing CIE coordinate with different bias voltage.
　The major materials we used in this experiment were NPB, DVBPi, Rubrene, BCP, Alq3 and Al. NPB was used as hole-transporting layer, DPVBi was used as blue-emitting layer and host material, Rubrene was used as orange-emitting fluorescence and gust material, BCP was used as hole-blocking layer, Alq3 was used as electron-transporting layer and Al was used as cathode. It is the most important in this experiment is finding the optimum deposition rate for DPVBi and Rubrene in coevaporation and changing the dopant location of Rubrene to discuss the light characteristics. The different deposition rate in coevaporation would affect the efficiency of energy transfer. Therefore, in this experiment, we could obtain optimum mixing-light effect by incomplete energy transfer.
　Originally, from the experiment results, we could obtain incomplete energy transfer when the deposition rate in coevaporation was 1：0.05. If the deposition rate in coevaporation was higher than 1：0.05, the device would emit orange light. If the deposition rate in coevaporation was lower than 1：0.05, the device would emit blue and orange light. In this experiment, the optimum thickness of each materials was that NPB(200Å)、DPVBi：Rubrene(250Å)、BCP(50Å)、Alq3(200Å).
　Next, we separated the DPVBi layer into two parts, one part was doped-Rubrene layer, another was undoped layer. And then we changed the location of the two parts to discuss the emitting-light effect. In this experiment, we obtained the optimum structure was NPB / DPVBi：Rubrene / DPVBi / BCP / Alq3 / Al. And than we adjusted the deposition rate in coevaporation and found the optimum deposition rate was 1：0.006 and the CIE coordinate was on (0.31 , 0.35). The luminance was 3833 at 11V.

Reference
[1] Pope,M., kallmann, H.P. and Magnante, P., J. Chem. Phys, 38, p.2042, 1963
[2] Helfrich, W. and Schneider, W.G., Phys.Rev.Lett., 14, p.229, 1965
[3] Tang, C.W. and VanSlyke, S.A., Appl. Phys. Lett., 51, p.913, 1987
[4] J.H. Burroughes, D. D. C Bradley, A, R. Brown, R. N. Marks, K. Mackly, R. H. Friend, P. L. Burn, and A. B. Homes, Nature, 347, 539(1990)
[5] Gang Cheng, Feng Li, Yu Duan, Jing Feng, and Shiyong Liu, Song Qiu, Dong Liu, and Yuguang Ma, S. T. Lee, Apl, vol 82, no 24(2003)
[6] A. A. Schoustikov, Y. You, and M. E. Thompson, “Electroluminescence color tuning by dye doping in OLED”, IEEE J. Select. Topics Quantum Electron., vol. 4, pp. 3-13, Jan. 1998
[7] X. T. Tao, S. Miyata, H. Sasabe, G.J. Zhang, T. Wada, and M. H. Jiang, “Efficient organic red electroluminescent device with narrow mission peak”, Apple. Phys. Lett., vol. 78, no. 3, pp. 279-281,(2001)
[8] V. Bulovis’ , A. Shoustikov, M. A. Baldo, E. Bose, E. Bose, V. G. Kozlov, M. E.Thompson, and S. R. Forrest, Chem. Phys. Lett. 287, 455(1998).
[9] 3M. A. Baldo, Z. G. Soos, and S. R. Forrest, Chem. Phys. Lett. 347, 297(2001)
[10] G. Y. Zhong, J. He, S. T. Zhang, Z.Xu, Z. H. Xiong, H. Z. Shi, X. M. Ding, W. Huang, and X. Y. Hou, Apple. Phys. Lett. 80 4846(2002).
[11] K. O. Cheon and J. Shinar, Appl. Phys. Lett. 81, 1783(2002).
[12] C. W. Tang, S. A. VanSlyke, and C. H. Chen, J. Appl. Phys. 65, 3610,(1987).
[13]Oppenheimer, J. R. Pev., 60, 158(1941)
[14] Förster, Th. Ann. Phys. (Leipz), 2, 55(1959)
[15]T. Förster, Discuss. Faraday Soc. 7, 27(1959)
[16]N. j. Turo, Mondern Molecular Photochemistry (Benjamin/Cummings, Menlo Park, CA), Chapt. 9(1983)
[17]J. r. Lakowicz, Principles of fluorescence Spectros(Plentum, New York), Chap. 10(1983)
[18] V. G. Kozlov, V. Bulovic, P. E. Burrows, M. Baldo, V. B. Khalin, G. Parthasarathy, S. R. Forrest, Y. You, and M. E. Thompson, “Study of lasing action based on Förster energy transfer in optically pumped organic semiconductor thin films” J. Appl. Phys., vol.84, no. 8, pp.4096-4108, 1998.
[19] A. A. Shoustikov, Y. You, and M. E. Thompson, “Electroluminescence color tuning by dye doping in organic light-emitting diodes” IEEE J. Select. Topics Quantum Electron, vol. 4, pp. 3-13, Jan. 1998.
[20] K. Read, H. S. Karlsson, M. M. Murnane, H. C. Kapteyn, and R. Haight, “Excitation dynamics of dye doped tris(8-hydroxyquinoline) aluminum films studied using time-resolved photoelectron spectroscopy” J. Appl. Phys., vol. 90, no.1, pp.294-300, 2001.
[21] Chengfeng Qiu, haiying Chen, Man Wong, Senior Member, IEEE, and Hoi S. Kwok, IEEE Transactions on Electron Devices, vol. 49, no. 9 September 2002.
[22] Jianmin Shi and C. W. Tang, Appl. Phys. Lett. 70(13), 31 March 1997.
[23] A. R. Brown, D. D. C. Bradley, J. H. Burroughes, R. H. Frienf, N. C. Greenham, P. L. Burn, A. B. Holmes, and A. kraft, Appl. Phys. Lett. 61, 2793(1992).
[24] M. Pope and C. E. Swenberg, Electronic Processes in Organic Crystals (Oxford University Press, Oxford, 1982).
[25] K. O. Cheon and J. Shinar(unpublished).
[26] N. von Malm, J. Steiger, R. Schmechel, and H. von Seggern, J. Appl. Phys. 89, 5559 (2001).
[27] J. Littman and P. Marticm, J. Appl. Phys. 72, 1957 (1992).
[28] S. Johnson, Draft review Chapter submitted to OIDA, July 2000.
[29] H. Becker, et al., Phys. Rev. B 56, 1893(1997).
[30] S. Forrest, M. Thompson, MRS Spring Meeting, San Francisco, 2002, OIDA OLED Workshop, April 5, 2002.
[31] Baldo et al., Phys. Rev. B62, 10967(2000).
[32] Young et al., Appl. Phys Lett. 80, 874(2002).
[33] Szmytkowski et al, Appl. Phys. Lett., 80, 1465(2002).
[34] R. C. Kwong, M. R. Nugent, T. Ngo, K. Rajan, L. Michalski, M. S.Weaver, T. X. Zhou, Y-J. Tung, R. Hewitt, M. Hack, J. J. Brown, Ewing, NJ., Meeting of the society for Information Display, Boston, May 20-24, 2002, presentation 52.3.
[35] I. Schnitzer and E. Yablonovich, Appl. Phys. Lett., 63, 2174(1993).
[36] G. Gu et al., Opt. lett. 22, 396(1997).
[37] C. Madigan et al., Appl. Phys. Lett. 76, 1650(2000).
[38] Milan Stolka, Consultant, OIDA OLED Workshop August, 2002.
[39] J. Zhao, S. Xie, S. Han, Z. Yang, L. Ye, and T. Yang, Synth. Met. 114, 251(2000).
[40] A. Andersson, N. Johansson, P. Broms, N. Yu, D. Lupo, and R. Salaneck, Adv. Mater. 10, 857(1998).
[41] H. Kim, J. S. Horwitz, G. P. Kushto, S. B. Qadri, Z. H. Kafafi, and D. B. Chrisey, Appl. Phys. Lett. 78, 1050(2001).
[42] A. Yamamori, S. Hayashi, T. Koyama, and Y. Taniguchi, Appl. Phys. Lett. 78, 3343(2001).
[43] I-Min Chan, Tsung-Yi Hsu, and Franklin C. Hong, Appl. Phys. Lett, vol 81, no 102 (2002).
[44] F. Li, H. Tang, J. Shinar, O. Resto, and S. Z. Weisz, Appl. Phys. Lett. 70, 2741 (1997).
[45] C. C. Wu, C. I. Wu, J. C. Sturm, and A. Kahn, Appl. Phys. Lett. 70, 1348 (1997).
[46] I. M. Chan, W. C. Cheng, and F. C. Hong, Appl. Phys. Lett. 80, 13 (2002).
[47] S. K. So, W. K. Choi, C. H. Cheng, L. M. Leung, and C. F. Kwong, Appl. Phys. A:Mater. Sci. Process. A68, 447(1999).
[48] S. F. J. Appleyard and M. R. Willis, Opt. Mater. 9, 120 (1998).
[49] H. Y. Yu, X. D. Feng, D. Grozea, Z. H. Lu, R. N. S. Sodhi, A.-M. Hor, and H. Aziz, Appl. Phys. Lett. 78, 2595 (2001).
[50] S. T. Lee, Z. Q. Gao, and L. S. Hung, Appl. Phys. Lett. 75, 1404 (1999).
[51] Sun Woong Kim, Byong Hoon Hwang, Joo Hyeon Lee, Jae IK Kang, Kyoung Wook Min, Woo Young Kim, Current Applied Physics 2, 335-338(2002).
[52] C. W. Tang, S. A. Vanslyke, and C. H. Chen, J. Appl. Phys. 65, 3610 (1989).
[53] J. Shi and C. W. Tang, J. Appl. Phys. 70, 1665 (1997).
[54] J. Nakada and T. Toma, Inorganic and Organic Electroluminescence/EL’96, Berlin, P.385, Wissenschaft und Technik Verlag, Berlin (1996).
[55] E. Han, l. Bo, Y. Niidome, and M. Fujihira, Cjen. Lett, P. 969(1994).
[56] S. Tokito and Y. Taga, Appl. Phys. Lett. 66, 673(1995).
[57] S. A. VanSlyke, C. H. Chen, and C. W. Tang, Appl. Phys. Lett. 69, 2160 (1996).
[58] Y. Shen, D. B. Jacobs, G. G. Malliaras, G. Koley, M. G. Spencer, and A. Orannidis, Adv. Mater. 13, 1234(2001).
[59] C. Qiu, H. Chen, Z. Xie, M. Wong, and H. S. Hwok, Appl. Phys. Lett. 80, 3485(2002).
[60] I.-M. Chan, T.-Y. Hsu, and F. C. Hong, Appl. Phys. Lett. 81, 1899(2002).
[61] Chengfeng Qiu, Zhilang Xie, Haiying Chen, Man Wong, and Hoi Sing Kwok, JAP, vol 93, no 615(2003).
[62] J. Kido, M. Kimura, and K. Nagai, Science 267, 1332(1995).
[63] R. S. Deshpande, V. Bulovic, and S. R. Forrest, Appl. Phys. Lett. 75, 888(1999).
[64] Ch. Janda, A. B. R. Mayer, and W. Grothe, J. Appl. Phys. 85, 6884(1999).
[65] T. M. Brown, R. H. Friend, I. S. Millard, D. J. Lacey, J. H. Burroughes, and F. Cacialli, Appl. Phys. Lett. 79, 174(2001).
[66] L. S. Hung, C. W. Tang, and M. G. Mason, Appl. Phys. Lett. 70, 152 (1997).
[67] G. E. Jabbour, B. Kippelen, N. R. Armstrong, and N. Peyghambarian, Appl. Phys. Lett. 73, 1185(1998).
[68] J. Kido and T. Matsumoto, Appl. Phys. Lett. 73, 2866 (1998).
[69] L. S. Hung, C. W. Tang, M. G. Mason, P. Raychaudhuri, and J. Madathil. Appl. Phys. Lett. 78, 544 (2001).
[70] L. S. Hung and M. G. Mason, Appl. Phys. Lett. 78, 3732(2001).
[71] T. M. Brown, R. H. Friend, I. S. Millard, D. J. Lacey, J. H. Burroughes, and F. Cacialli, Appl. Phys. Lett. 77, 3096 (2000).
[72] H. Fujikawa, T. Mori, K. Noda, M. Ishii, S. Tokito, and Y. Taga, J. Lumin. 87-89, 1177(2000).
[73] 10M. K. Fung, S. L. Lai, S. W. Tong, M. Y. Chan, C. S. Lee, S. T. Lee, W. W. Wu, M. Inbasekaran, and J. J. O’Brien, Appl. Phys. Lett. 81, 1497(2002).
[74] J. M. Bharathan and Y. Yang, J. Appl. Phys. 84, 3207(1998).
[75] M. Stossel, J. Staudigel, F. Steuber, J. Simmer, and A. Winnacke, Appl. Phys. A:Mater. Sci. Process. 68, 387(1999).
[76] S. C. Kim, S. N. Kwon, M. W. Choi, C. N. Whang, K. Jeong, S. H. Lee, J. G. Lee, and S. Kim, Appl. Phys. Lett. 79, 3726(2001).
[77] M. Matsumura, A. Tto, and Y. Miyamae, Appl. Phys. Lett. 75, 1042 (1999).
[78] L. S. Hung, C. W. Tang, and M. G. Mason, Appl. Phys. Lett. 70, 152 (1997).
[79] Chengfeng Qiu, Zhilang Xie, Haiying Chen, Man Wong,a) and Hoi Sing Kwok, JAP, vol 93,no 6 , (2003).
[80] M. G. Mason, C. W. Tang, L. S. Hung, P. Raychaudhuri, J. madathil, D. J. Giesen, L. Yan, Q. T. Le, Y. Gao, S. T. Lee, L. S. Liao, L. F. Cheng, W. R. Salaneck, D. A. Dos Santos, and J. L. Bre’das, J. Appl. Phys. 89, 2756(2001).
[81] Q. T. Le, L. Yan, Y. Gao, M. G. Mason, D. J. Giesen, and C. W. Tang, J. Appl. Phys. 87, 375(2000).
[82] H. Heil, J. Steiger, S. Karg, M. Gastel, H. Ortner, H. Von Seggern, and M. Sto”Bel, J. Appl. Phys. 89, 420(2001).
[83] 14V. E. Choong, M. G. Mason, C. W. Tang, and Yongli Gao, Appl. Phys. Lett. 72, 2689(1998).
[84] M. Y. Chan, S. L. Lai, M. K. Fung, S. W. Tong, C. S. Lee,a) and S. T. Lee, Appl. Phys. Lett. Vol 82, no 11(2003).