摘 要

藍色磷光材料為利用吡唑苯環配位基搭配雙氮配位基作為第三配位基進而成功合成出新型八面體之銥金屬錯合物，可分成兩大系列：第一系列為吡唑苯環-五雜環-吡啶配位基之銥金屬錯合物，第二系列為吡唑苯環-吡唑-咪唑配位基之銥金屬錯合物。針對藍色磷光之銥金屬錯合物做一系列的研究包括吸收波長、放光波長(室溫、低溫)和HOMO與LUMO能階測量，兩部分的材料皆能夠在室溫下散發出藍色磷光，最短波長可達深藍範圍為438、464、496 nm。較佳的元件為使用sean111，其放光波長為454、482 nm，□ext效率(即對外量子放光效率)為1.2 %，CIE (0.14, 0.17)。

矽主體之芳香環衍生物(BSi、BSiB、BSiCN和BSiPN )是以矽原子阻隔整體分子的共振結構，且利用耦合方式引入dimesitylboron和胺基苯類兩種取代基來作為藍色磷光材料的主層材料。此系列的材料除了有良好的熱穩定性(Tg、Tm)外，還具有高的三重態能階(2.9 eV以上)，以符合藍色磷光材料的需求。使用FIrpic之元件的□ext效率高達9.6 %，CIE (0.14, 0.29)；另外(dfppy)2Ir(pytz)之元件的□ext效率可達8.2 %，CIE (0.13, 0.21)。

胺基苯三蝶烯衍生物係(TCTP和TPTP)以剛性架橋的結構來阻斷分子結構的共振性並導入胺基苯類的取代基，材料本身不但同樣保有高的三重態能階(2.9 eV以上)，還具有極佳的熱性質(極高的Tg, Tm)。此系列的材料不僅適用在藍色磷光材料上，亦可運用在綠色和紅色磷光材料上。FIrpic藍光元件的□ext效率高達10.1 %，CIE (0.14, 0.36)；(dfppy)2Ir(pytz)藍光元件的□ext效率達7.9 %，CIE (0.14, 0.22)。此外Ir(ppy)3綠光元件的□ext效率高達11.5 %，CIE (0.23, 0.66)；Ir(DBQ)2(acac)橘紅光元件的□ext效率可達9.8 %，CIE (0.62, 0.38)。FIrpic與Ir(DBQ)2(acac)混合雙波段白光元件之□ext效率高達8.5 %，CIE (0.32, 0.33)＠8 V。

有機螢、磷光材料之三波段白光元件研究係利用藍色螢光材料T1和T2與綠色Ir(ppy)3、紅色Ir(DBQ)2(acac)磷光材料成功整合製作的白光元件。T1與T2之最佳元件的□ext效率分別為6.2和7.0 %，最大亮度分別高達58343和75264 cd/m2，極穩定的CIE(0.34, 0.33)和(0.33, 0.33)，良好的CRI = 81和74。

使用混合層NPB:C60插入ITO和電洞傳輸層(NPB)之間；其總厚度為7 nm，摻雜濃度為25-50 %時，可使整體元件的效能增加約30 %，包括對外量子放光效率(□ext)、電流效率(□c)、能量效率(□p)等。最佳化的條件[NPB:C60(50%) (7 nm)]應用於C545T的元件上，元件亦有增加約30 %的效果。

Abstract

We have presented the syntheses of more deep blue iridium complexes with using the 3-phenylpyrazole ligands and new third ligands to form the typical cyclometalated (C^N) chelation and typical anionic (N^N) chelation for iridium center, respectively. According to the third ligands (N^N), they can be divided into two series: One is 2-pyridylpyrazole with five-six member rings, the other is 1-imidazolylpyrazole with five-five member rings. Physical properties, including UV-vis absorption, emission spectra in CH2Cl2 or solid crystal at room temperature, and HOMO and LUMO energy levels of these blue phosphorescent materials were checked. Most of these compounds emit room-temperature blue light and the more deep blue emission was located around 438, 464 and 496 nm. When using sean111 as dopant, the device shows emission peaks at 454, 482 nm, maximum brightness of 4299 cd/m2, maximum external quantum efficiency of 1.2 % and good CIE coordinates of (0.14, 0.17).

Heteroatom-center-arylsilane derivatives (BSi, BSiB, BSiCN and BSiPN) were synthesized as novel host materials for deep blue or greenish-blue phosphorescent dopants. These materials not only have good thermal stability (melting point and glass-transition temperature) but also high triplet-state energy level above 2.9 eV. The devices with FIrpic or (dfppy)2Ir(pytz) doped in them have high luminous efficiencies, including external quantum efficiency, current efficiency and power efficiency. The maximum external quantum efficiencies of BSi:FIrpic and BSiB:(dfppy)2Ir(pytz) devices were 9.6 % with the CIE coordinates of (0.14, 0.29) and 8.2 % with the CIE coordinates of (0.13, 0.21), respectively.

Triarylaminotriptycene derivatives were conveniently prepared as host materials for RGB phosphorescent dopants. TCTP and TPTP exhibit excellent thermal stability and a high melting point, especially TCTP (Tg = 238 ℃, Tm = 378 ℃). Both of them have high triplet-state energy level (above 2.9 eV) improved the host–guest energy transfer to blue phosphorescent materials, but TPTP with lower triplet energy of 2.94 eV also can be used as a host for green and red phosphorescent materials. The blue devices of FIrpic and (dfppy)2Ir(pytz) show maximum external quantum efficiency of 10.1 % and 7.9 %, and the CIE coordinates of (0.14, 0.36) and (0.14, 0.22), respectively. The green device of TPTP:Ir(ppy)3 exhibits maximum external quantum efficiency of 11.5 % with the CIE coordinates of (0.23, 0.66). For the red device of TPTP:Ir(DBQ)2(acac) with the CIE coordinates of (0.62, 0.38), the maximum external quantum efficiency of 9.8 % is achieved. The two emission zones for white light device by employing FIrpic and Ir(DBQ)2(acac) have the maximum external quantum efficiency of 8.5 % and the CIE coordinates of (0.32, 0.33) at 8 V.

We have demonstrated the white light-emitting devices with high brightness, and great external quantum efficiency and current efficiency from blue fluorescent (T1) or (T2) and green (Ir(ppy)3) and red (Ir(DBQ)2(acac) or Ir(MDQ)2(acac)) phosphorescent materials. The white EL spectra with the very stable three emission zones were contributed from three materials. In addition, they own very stable white CIE coordinates (0.34, 0.33) and (0.35, 0.37) and high CRI from 6 V to 15 V. The devices with the structure [NPB/CBP:Ir(DBQ)2(acac)/CBP: Ir(ppy)3/ T1 or T2 / Electron transporting materials show bright white light and good luminous efficiencies] .

C60 doping in the thin hole transport materials as a hole-injection layer of an organic electroluminescent devices can improve the luminous efficiencies, including the maximum current efficiency and power efficiency at the same voltage and current density. When the concentrations of fullerene (C60) doped in NPB (7 nm) were varied between 25%-50%, the luminescence efficiencies also increased more than 30%. In addition, application in the general devices using C545T as a green dopant emitter in Alq has the same effects under similar conditions.

參考文獻：
1.Burrows, P. E.; Gu, G.; Bulovic V.; Shen, Z.; Forrest, S. R.; Thompson, M. E. IEEE Trans. Electron Device 1997, 44, 11888.
2.Pope, P.; Kallmann, H. P.; Magnante, P. J. Chem. Phys. 1963, 38, 2042.
3.Tang, C. W.; VanSlyke, S. A. Appl. Phys. Lett. 1987, 51, 913.
4.Burroughes, J. H.; Bradley, D. D. C.; Brown, A. R.; Marks, R. N.; Mackay K. D.; Friend R.H.; Burn P. L.; Holmes A. B. Nature 1990, 347, 539.
5.審譯：林敬二, 林宗義,儀器分析第四版, 1994, 上冊, 174 – 193.
6.N. J. Turro, Modern Molecular Photochemistry, University Science Book, CA, 1991
7.T. Forster. Disc. Faraday Soc. 1959, 27, 7
8.D. L. Dexter. J. Chem. Phys. 1953, 21, 836
9.M. A. Baldo, D. F. O’ Brien, M. E. Thomspon, S. R. Forrest, Phys. Rev. B 1999,60, 20
10.Text book of Basic Optics.
11.G. Gu, D. z. Garbuzov, P. E. Burrows, S. Venkatesh, S. R. Forrest, and M. E. Thompson, Opt. Lett. 22, 396(1997).
12.T. Tsutsui and S. Satio, in Intrinsically Conducting Polymer: An Emerging Technology, edited by M. Aldissi, Kluwer Academic, Dordreccht 1993, p. 123.
13.T. Ishida, H. Kobayashi, Y. Nakato, J. Appl. Phy. 1993, 73, 4344
14.J. S. Kim, M. Granatrom, R. H. Friend, N. Johansson, W. R. Salaneck, R. Daik, W. J. Feast, F. Cacialli, J. Appl. Phy. 1998, 84, 6859
15.S. K. Sol, W. K. Choi, C. H. Cheng, L. M. Leung, C. F. Kwong, Appl. Phys. A 1999, 68, 447

16.M. G. Mason, L. S. Hung, C. W. Tang, S. T. Lee, K. W. Wong, M Wang, J. Appl. Phy. 1999, 86, 1688
17.S. A. VanSlyke, C. H. Chen, C. W. Tang, Appl. Phys. Letter. 1996, 69, 2160
18.(a) Y. Shirota, Y. Kuwabara, H. Inada, Appl. Phys. Lett. 1996, 69, 2160 (b)Y. Hamada, N.Matsusue, H. Kanno, Hfujii, Tsujioka, H. Takahashi, Jpn. J. Appl. Phys. Part 2, 40, L753 (2001) (c)D. Heithecker, A. Kammoun, T. Dobbertin, T. Riedl, E Becker, D. Metzdorf, D. Schneider, H. H. Johannes, and W. Kowalsky Appl.phys.Lett. 2003 82, 4178
19.A. Elschner, F. Bruder, H. W. Heuer, F. Jonas, A. Karbach, S. Kirchmeyer, S. Thurm, R. Wwhrmann, Synth. Met. 2000, 111 39
20.Y. Shirota, K. Okumoto, H. Inada, Synth. Met. 2000, 111, 387
21.M. Stolka, J.F. Janus, D.M. Pai, J. Phys. Chem. 1984, 88, 4707
22.B. Chen, C.-S. Lee, S.-T. Lee, P. Webb, Y.-C. Chan, W. Gambling, H.Tian and W. Zhu, Jpn. J. Appl. Phys. Part 1 2000, 39, 1190
23.U. Bach, K. D. Cloedt, H. Spreitzer, M. Gratzel, Adv. Mater., 2000, 12, 1060
24.Y. Kuwabara, H. Ogawa, H. Inada, N. Noma and Y. Shirota, Adv. Mater., 1994, 6, 677.
25.J. D. Anderson, E. M. Mcdonald, P. A. Lee, M. L. Anderson, E. L. Ritchie, H. K. Hall, T. Hopkins, E. A. Mash, J. Wang. A. Padias, S. Thayumanavan, S, Barlow, S. R. Marder, G. E. Jabbour, S. Shaheen, B. Kippelen, N. Peyghambarian, R. M. Wightman, N. R. Armstrong, J. Am. Chem. Soc., 1998, 120, 9646
26.Y. T. Tao, E. Balasubramaniam, A. Danel, B. Jaeosa, P. Tomasil, Appl. Phys. Lett., 2000, 77, 1575. Y. T. Tao, E. Balasubramaniam, A. Danel, B. Jaeosa, P. Tomasil, Appl. Phys. Lett., 2000, 77, 933.
27.Y. Kijima, N. Asai, and S. Tamura, Jpn. J. Appl. Phys. Part 1, 1999, 38, 5274.
28.J. Kido, C. Ohtaki, K. Honhawa, K. Okuyama, Nagai, Jpn. J. Appl. Phys., 1993, Part 2, 32 (7A), L917.
29.M. A. Baldo, S. Lamansky, P. E. Burrows, M. E. Thompson, S. R. Forrest, Appl. Phys. Lett., 1999, 75, 4.
30.C. Adachi, M. A. Baldo, M. E. Thompson, S. R. Forrest, J. Appl. Phys., 2000, 90, 5048.
31.W. S. Huang, J. T. Lin, C. H. Chien, Y. T. Tao, S. S. Sun, and Y. S. Wen, Chem. Mater. 2004, 16, 2480.
32.M. A. Baldo, M. E. Thompson, S. R. Forrest, Nature, 2000, 403, 750.
33.C. Adachi, M. A. Baldo, S. R. Forrest, S. Lamansky, M. E. Thompson, R. C. Kwong, J. Am. Chem. Soc., 2001, 78, 1622.
34.J. P. Duan, P. P. Sun, C. H. Cheng, Adv. Mater., 2003, 15, 224.
35.C. Adachi, R. C. Kwong, P. Djurovich, V. Adamovich, M. A. Baldo, M. E. Thompson, S. R. Forrest, Appl. Phys. Lett., 2001, 79, 2082.
36.R. J. Holmes, S. R. Forrest, Y.-J. Tung, R. C. Kwong, J. J. Brown, S. Garon and M. E. Thompson, Appl. Phys. Lett., 2003, 82, 2422.
37.S. Tokito, T. Iijima, Y. Suzuri, H. Kita, T. Tsuzuki, F. Sato, Appl. Phys. Lett., 2003, 83, 569.
38.a) R. J. Holmes, B. W. D’Andrade, S. R. Forrest, X. Ren, J. Li, M. E. Thompson, Appl. Phys. Lett., 2003, 83, 3818. b) X. Ren, Jian Li, R. J. Holmes, P. I. Djurovich, S. R. Forrest, M. E. Thompson, Chem. Mater. 2004, 16, 4743-4747.
39.A. B. Tamayo, B. D. Alleyne, P. I. Djurovich, S. Lamansky, I. Tsyba, N. N. Ho, R. Bau, M. E. Thompson, J. Am. Chem. Soc., 2003, 125, 7377.
40.J. Li, P. I. Djurovich, B. D. Alleyne, M. Yousufuddin, N. N. Ho, J. C. Thomas, J C. Peters, R. Bau, M. E. Thompson, Inorg. Chem. 2005, 44, 1713-1727.
41.C. H. Yang, S. W. Li, Y. Chi, Y. M. Cheng, Y. S. Yeh, P. T. Chou, G. H. Lee, C. H. Wang , C. F. Shu, Inorg. Chem. 2005, 44, 7770-7780.
42.S. J. Yeh, M. F. Wu, C. T. Chen, Y. H. Song, Y. Chi, M. H. Ho, S. F. Hsu, C. H. Chen, Adv. Mater., 2005, 17, 285.

43.M. H. Tsai, H. W. Lin, H. C. Su, T. H. Ke, C. C. Wu, F. C. Fang, Y. L. Liao, K. T. Wong, C.-I Wu, Adv. Mater., 2006, 18, 1216.
44.M. Ikai, S. Ichinosawa, Y. Sakamoto, T. Suzuki, Y. Taga, Appl. Phys. Lett., 2001, 79, 156.
45.G. T. Lei, L. D. Wang, L. Duan, J. H. Wang, Y.Qiu, Syhth. Met., 2004, 144, 249.
46.Synthesis of Pyridyl Triazole and Pyridyl Imidazole Based Iridium Complexes: Application in Organic Light-Emitting Devices, 廖偉賢, 國立清華大學碩士論文, 民國94年七月
47.C. Zhang, C. F. Chen, J. Org. Chem., 2006, 71, 6626-6629
48.Synthesis of Pyrazole Based Iridium Complexes and Application in OLED, 湯庭瑋, 國立清華大學碩士論文, 民國95年夏
49.B. W. D'Andrade, M. E. Thompson, S. R. Forrest, Adv. Mater., 2002, 14, 147.
50.S. Tokitoa, T. Iijima, T. Tsuzuki, F. Sato, Appl. Phys. Lett., 2003, 82, 2459.
51.B. W. D'Andrade, R. J. Holmes, S. R. Forrest, Adv. Mater., 2004, 16, 624.
52.G. Lei, L. Wanga, Y. Qiub, Appl. Phys. Lett., 2006, 88, 103508.
53.G, Schwartz, K. Fehse, M. Pfeiffer, K. Walzer, K. Leo, 2006, 89, 083509.
54.Z. Chen, J. Yu, Y. Sakuratani, M. Li, M. Sone, S. Miyata, T. Watanabe, X. Wang, H. Sato, J Appl. Phys., 2001, 89, 7895.
55.J. Y. Lee, J. H. Kwon, Appl. Phys. Lett., 2005, 86, 063514.
56.X. D. Feng, C. J. Huang, V. Lui, R. S. Khangura, and Z. H. Lua, Appl. Phys. Lett., 2005, 86, 143511.
57.S. Han, C. Huang, and Z.-H. Lua, J Appl. Phys., 2005, 97, 093102.
58.C. H. Chen, C. W. Tang, Appl. Phys. Lett., 2001, 79, 3711.
59.S. Uchida, J. Xue, B. P. Rand, and S. R. Forrest, Appl. Phys. Lett., 2004, 84, 4218.
60.Janietz, S.; Bradley, D. D. C.; Grell, M.; Giebeler, C.; Inbasekaran, M.; Woo, E. P. Appl. Phys. Lett. 1998, 73, 2453
61.Burrows, P. E.; Shen, Z.; Bulovic, V.; McCarty, D.M.; Forrest, S. R. J. Appl. Phys. 1996, 79, 7991