本論文是以串聯的概念，製作高效率之串聯式(tandem)有機發光二極體(Organic light emitting diode；OLED)元件，將上、下兩個相同的高效率綠光元件，以二極體n-type/p-type連接層連接起來，與傳統的有機電激發光二極體元件比較，在相同的電流密度下，串聯式元件擁有較高的發光效率。本實驗室原未發展過串聯式元件，此串座元件的開發則針對串接平台的建立，以及高效率串接元件兩大重點進行研究探討，本論文實驗主軸主要分為：（Ⅰ）以磷光材料Ir(ppy)3做為磷光電激發光材料，經由材料挑選與最佳化，製作出高效率綠光有機發光二極體。（Ⅱ）藉由文獻探討做為參考，選用n-doping/Metal Oxide做為串聯式元件的連接層，進行連接層研究與串接式結構平台建立。（Ⅲ）結合高效率綠光標準元件與發展出之串聯式結構，進行元件最佳化，製作出超高效率串聯式綠光元件。
（Ⅰ）經由材料挑選、能階匹配、發光層之摻雜濃度、厚度最佳化後的元件，其發光效率在100 cd/m2的亮度下，驅動電壓為3.7 V，電流效率63.8 cd/A；在1000 cd/m2的亮度下，驅動電壓為4.6 V，電流效率可達到60.0 cd/A。以上特性表現在小分子磷光綠光系統裡都是非常出色的。
（Ⅱ）藉由串接綠色與藍色發光元件之設計，來確保連接層前後之元件皆有得到載子並復合放光。再進行連接層的摻雜濃度與厚度最佳化，成功的建立了串接式結構製作平台，其串接效果，可達到理論電流效率疊加之效果。
（Ⅲ）在擁有良好基本元件以及確定連接層結構後，我們成功地將高效率標準元件與連接層做結合，串接出超高效率之綠光元件，此結構在1000 cd/m2的亮度下，可以達到98 cd/A之發光效率。

In this thesis, we produce high efficiency green organic light-emitting diode (OLED) with tandem structure based on the concept of tandem structure, and connect two identical high efficiency green light-emitting diodes (upper and lower) by n-type diode layer. Compared with traditional organic light emitting diode, stacked devices have higher emitting efficiency at the same current density. Our laboratory has no experience in establishing stacked device before; the development of stacked device mainly focuses on two issues: the establishment of tandem platform and high-efficiency stacked device. Experiments involved in the thesis mainly focus on: （Ⅰ）Taking phosphorescent material Ir(ppy)3 as the material of electrophosphorescence, and make high-efficiency organic green emitting diode by material selection and optimization（Ⅱ） Taking n-doping/Metal Oxide as the connecting layer of stacked devices as literature review suggests, and then analyze connecting layer and establish tandem platform.（Ⅲ）Proceeding device optimization by the combination of high-efficiency green emitting standard device and the tandem structure we established to produce super-efficient tandem green light-emitting devices.
（Ⅰ）After material selection, energy alignment and the optimization of thickness and impurity concentration in emitting layer, the current efficiency and driving voltage of stacked devices are 63.8 cd/A and 3.7 V respectively under the luminance of 100 cd/m2; The current efficiency and driving voltage of stacked devices are 60.0 cd/A and 4.6 V respectively under the luminance of 1000 cd/m2. The above-mentioned stats are very spectacular in small-moleculed phosphorescent green emitting system.
（Ⅱ）We make the devices before and after connecting layer have charge and recombine to emit by stacking green emitting device and blue emitting device. Afterward, we optimize the doped concentration and thickness, and successfully establish the manufacturing platform of stacked devices. The result of stacking can reach the effect in the theory of stacked current efficiency.
（Ⅲ）After possessing the premium basic devices and confirming the structure of connecting layer, we successfully connect high-efficiency devices and connecting layer, and stack the ultra-high-efficiency green emitting device. At the brightness of 1000 cd/m2, its current efficiency can reach 98 cd/A.

參考文獻
[1] J. Shinar and R. Shinar, "Organic light-emitting devices (OLEDs) and OLED-based chemical and biological sensors: an overview," J. Phys. D: Appl. Phys., 41, 133001 (2008).
[2] S. R. Forrest, "The path to ubiquitous and low-cost organic electronic appliances on plastic," Nature, 428, 911 (2004).
[3] http://www.samsung.com/
[4] http://www.lg.com/
[5] http://www.shopbiz.jp/en/lf/
[6] M. Pope, H. P. Kallmann and P. Magnante, "Electroluminescence in Organic Crystals," J. Chem. Phys., 38, 2042 (1963).
[7] W. Helfrich and W. G. Schneider, "Recombination Radiation in Anthracene Crystals," Phys. Rev. Lett., 14, 229 (1965).
[8] D. F. Williams and M. Schadt, "A simple organic electroluminescent diode," Proc. IEEE., 58, 476 (1970).
[9] P. S. Vincett, W. A. Barlow, R. A. Hann and G. G. Roberts, "Electrical conduction and low voltage blue electroluminescence in vacuum-deposited organic films," Thin Solid Films, 94, 171 (1982).
[10] C. W. Tang and S. A. VanSlyke, "Organic electroluminescent diodes," Appl. Phys. Lett., 51, 913 (1987).
[11] J. H. Burroughes, D. D. C. Bradley, A. R. Brown, R. N. Marks and K. Mackay, "Light-emitting diodes based on conjugated polymers," Nature, 347, 539 (1990).
[12] C. Adachi, S. Tokito, T. Tsutsui and S. Saito, "Organic Electroluminescent Device with a Three-Layer Structure," Jpn. J. Appl. Phys., 27, L713 (1988).
[13] M. Era, C. Adachi, T. Tsutsui and S. Saito, "Double-heterostructure electroluminescent device with cyanine-dye bimolecular layer as an emitter," Chem. Phys. Lett., 178, 488 (1991).
[14] J. Kido, M. Kohda, K. Okuyama and K. Nagai, "Organic electroluminescent devices based on molecularly doped polymers," Appl. Phys. Lett., 61, 761 (1992).
[15] J. Kido, M. Kimura and K. Nagai, "Multilayer White Light-Emitting Organic Electroluminescent Device," Science, 267, 1332 (1995).
[16] J. Kido, H. Shionoya and K. Nagai, "Single-layer white light-emitting organic electroluminescent devices based on dye-dispersed poly(N-vinylcarbazole)," Appl. Phys. Lett., 67, 2281 (1995).
[17] T. Chiba, Y.-J. Pu, R. Miyazaki, K.-i. Nakayama, H. Sasabe and J. Kido, "Ultra-high efficiency by multiple emission from stacked organic light-emitting devices," Org. Electron., 12, 710 (2011).
[18] 黃孝文 and 陳金鑫, "有機電激發光材料與元件," (2005).
[19] M. F. Lamorte and D. Abbott, "Analysis of AlGaAs-GaInAs cascade solar cell under AM 0-AM 5 spectra," Solid-State Electronics, 22, 467 (1979).
[20] J. K. Kim, E. Hall, O. Sjolund and L. A. Coldren, "Epitaxially-stacked multiple-active-region 1.55 mu m lasers for increased differential efficiency," Appl. Phys. Lett., 74, 3251 (1999).
[21] X. Guo, G.-D. Shen, G.-H. Wang, W.-J. Zhu, J.-Y. Du, G. Gao, D.-S. Zou, Y.-H. Chen, X.-Y. Ma and L.-H. Chen, "Tunnel-regenerated multiple-active-region light-emitting diodes with high efficiency," Appl. Phys. Lett., 79, 2985 (2001).
[22] Z. Shen, P. E. Burrows, V. Bulović, S. R. Forrest and M. E. Thompson, "Three-Color, Tunable, Organic Light-Emitting Devices," Science, 276, 2009 (1997).
[23] T. Matsumoto, T. Nakada, J. Endo, K. Mori, N. Kawamura, A. Yokoi and J. Kido, Proceedings of IDMC'03, p.413 (2003).

[24] L. S. Liao, K. P. Klubek and C. W. Tang, "High-efficiency tandem organic light-emitting diodes," Appl. Phys. Lett., 84, 167 (2004).
[25] W. Gao and A. Kahn, "Controlled p-doping of zinc phthalocyanine by coevaporation with tetrafluorotetracyanoquinodimethane: A direct and inverse photoemission study," Appl. Phys. Lett., 79, 4040 (2001).
[26] T. Matsumoto, T. Nakada, J. Endo, K. Mori, N. Kawamura, A. Yoko and J. Kido, "Late-News Paper: Multiphoton Organic EL device having Charge Generation Layer," SID Int. Symp. Digest Tech. Papers, 34, 979 (2003).
[27] T. Tsutsui and M. Terai, "Electric field-assisted bipolar charge spouting in organic thin-film diodes," Appl. Phys. Lett., 84, 440 (2004).
[28] C.-C. Chang, S.-W. Hwang, C. H. Chen and J.-F. Chen, "High-Efficiency Organic Electroluminescent Device with Multiple Emitting Units," Jpn. J. Appl. Phys., 43, 6418 (2004).
[29] L. S. Liao, W. K. Slusarek, T. K. Hatwar, M. L. Ricks and D. L. Comfort, "Tandem Organic Light-Emitting Diode using Hexaazatriphenylene Hexacarbonitrile in the Intermediate Connector," Adv. Mater., 20, 324 (2008).
[30] S. Hamwi, J. Meyer, M. Kroger, T. Winkler, M. Witte, T. Riedl, A. Kahn and W. Kowalsky, "The Role of Transition Metal Oxides in Charge-Generation Layers for Stacked Organic Light-Emitting Diodes," Adv. Funct. Mater., 20, 1762 (2010).
[31] T.-W. Lee, T. Noh, B.-K. Choi, M.-S. Kim, D. W. Shin and J. Kido, "High-efficiency stacked white organic light-emitting diodes," Appl. Phys. Lett., 92, 043301 (2008).
[32] H. Kanno, R. J. Holmes, Y. Sun, S. Kena-Cohen and S. R. Forrest, "White Stacked Electrophosphorescent Organic Light-Emitting Devices Employing MoO3 as a Charge-Generation Layer," Adv. Mater., 18, 339 (2006).
[33] Y. Chen, J. Chen, D. Ma, D. Yan, L. Wang and F. Zhu, "High power efficiency tandem organic light-emitting diodes based on bulk heterojunction organic bipolar charge generation layer," Appl. Phys. Lett., 98, 243309 (2011).
[34] Y. Chen, J. Chen, D. Ma, D. Yan and L. Wang, "Tandem white phosphorescent organic light-emitting diodes based on interface-modified C[sub 60]/pentacene organic heterojunction as charge generation layer," Appl. Phys. Lett., 99, 103304 (2011).
[35] C. Adachi, R. C. Kwong, P. Djurovich, V. Adamovich, M. A. Baldo, M. E. Thompson and S. R. Forrest, "Endothermic energy transfer: A mechanism for generating very efficient high-energy phosphorescent emission in organic materials," Appl. Phys. Lett., 79, 2082 (2001).
[36] T. Ishida, H. Kobayashi and Y. Nakato, "Structures and properties of electron-beam-evaporated indium tin oxide films as studied by x-ray photoelectron spectroscopy and work-function measurements," J. Appl. Phys., 73, 4344 (1993).
[37] S. A. Van Slyke, C. H. Chen and C. W. Tang, "Organic electroluminescent devices with improved stability," Appl. Phys. Lett., 69, 2160 (1996).
[38] H. Zhang, Y. Dai and D. Ma, "High efficiency tandem organic light-emitting devices with Al/WO[sub 3]/Au interconnecting layer," Appl. Phys. Lett., 91, 123504 (2007).
[39] T.-Y. Cho, C.-L. Lin and C.-C. Wu, "Microcavity two-unit tandem organic light-emitting devices having a high efficiency," Appl. Phys. Lett., 88, 111106 (2006).
[40] M. V. M. Rao, T.-S. Huang, Y.-K. Su and Y.-T. Huang, "Fullerene and Pentacene as a Pure Organic Connecting Layer in Tandem Organic Light Emitting Devices," J. Electrochem. Soc., 157, H69 (2010).
[41] W. D. Gill, "Drift mobilities in amorphous charge-transfer complexes of trinitrofluorenone and poly-n-vinylcarbazole," J. Appl. Phys., 43, 5033 (1972).
[42] R. M. Glaeser and R. S. Berry, "Mobilities of Electrons and Holes in Organic Molecular Solids. Comparison of Band and Hopping Models," J. Chem. Phys., 44, 3797 (1966).
[43] E. Pinotti, A. Sassella, A. Borghesi and R. Tubino, "Electrical characterization of organic semiconductors by transient current methods," Synth. Metals, 122, 169 (2001).
[44] C. Adachi, M. A. Baldo, M. E. Thompson and S. R. Forrest, "Nearly 100% internal phosphorescence efficiency in an organic light-emitting device," J. Appl. Phys., 90, 5048 (2001).
[45] J. Brinstock, G. He, S.Murano, A. Werner and O. Zeika, Proceedings of SID’08, p822 (2008).
[46] J. G. Jang and H. K. Shin, "High efficiency green phosphorescent organic light emitting device with (TCTA/TCTA0.5TPBi0.5/TPBi): Ir(ppy)3 emission layer," Thin Solid Films, 517, 4122 (2009).