簡易檢索 / 詳目顯示

回結果列表
研究生： 楊正憲
Yang, Cheng-Hsien
論文名稱： 有機發光二極體之紅色與綠色發光材料
Red and Green Emitters for Organic Light-Emitting Diodes
指導教授： 孫亦文
Sun, I-Wen
學位類別： 博士
Doctor
系所名稱： 理學院 - 化學系
Department of Chemistry
論文出版年： 2006
畢業學年度： 94
語文別： 英文
論文頁數： 129
中文關鍵詞： 銥金屬 、發光材料 、有機發光二極體
外文關鍵詞： organic light-emitting diodes, emitters, iridium
相關次數： 點閱：89  下載：1 
分享至:
查詢本校圖書館目錄 查詢臺灣博碩士論文知識加值系統 勘誤回報

    • 　　有機發光二極體元件由於深具潛能並可應用於面板產業，近幾年來已經吸引部份學者的目光，並進行了廣泛的研究。這份研究主要針對紅光及綠光銥金屬磷光錯化合物等發光材料在有機發光二極體元件的應用上進行探討。此研究主要分為三個部份。

    　　第一部份，報告中合成出四支紅光銥金屬磷光錯化合物-(piq)2Ir(acac)、(1-niq)2Ir(acac)、(2-niq)2Ir(acac)及(m-piq)2Ir(acac)，並且對所有錯合物的化學及光物理性質皆充分研究。發光元件結構為ITO / NPB / CBP : Dopant / BCP / AlQ3 / LiF / Al，所有錯合物發光區皆落於620~680 nm之間。其中(m-piq)2Ir(acac)在電流密度300 mA/cm2下具有最高亮度17164 cd/m2，在電流密度20 mA/cm2下具有最高效率8.91 cd/A。而(1-niq)2Ir(acac)的色純度最佳，CIE座標為(x = 0.701, y = 0.273)。

    　　第二部份，報告中合成出三支紅光銥金屬磷光錯化合物-(pqz)2Ir(acac)、(1-mniq)2Ir(acac) 及 (2-mniq)2Ir(acac)，並且對所有錯合物的化學及光物理性質皆充分研究。其中(pqz)2Ir(acac)的配位基因為氮原子電負度的關係產生了與(2-mniq)2Ir(acac) π共軛系統延伸效應相同的紅位移。在此篇研究中，利用了密度泛函理論(DFT)以及時間密度泛函理論(TDDFT)計算工具對此錯合物進行計算，結果發現計算值與實驗值吻合。發光元件結構為ITO / NPB / CBP : Dopant / BCP / AlQ3 / LiF / Al，(pqz)2Ir(acac)為摻雜物時，元件色光為有效率的深紅色，CIE座標為(x = 0.70, y = 0.30)。

    　　第三部份，報告中利用真空純化系統在高溫、高真空下昇華銥金屬二聚物，可以很輕易的獲得不對稱的merdional 銥金屬錯合物。其中，mer-Ir(m-ppy)3 顛覆了一些光物理上的觀念，它具有與facile銥金屬錯合物如fac-Ir(ppy)3, fac-Ir(m-ppy)3相當的光物理性質。發光元件結構為ITO / NPB / CBP : Dopant / BCP / AlQ3 / LiF / Al，當以mer-Ir(m-ppy)3進行摻雜時，元件色光為較純之綠光，CIE座標為(x = 0.31, y = 0.59)，這個觀念提供了我們一個在設計摻雜物時一個新的思維。

    　Organic light-emitting diodes (OLEDs) have potentials for application in the flat panel display and have received vast attentions. This work focuses on synthesizing various green and red phosphorescent emitters based on iridium complexes.

    　Firstly, four novel red phosphorescent emitter compounds bis(1-phenyl- isoquinolinato-N,C2’)iridium(acetylacetonate), (piq)2Ir(acac), bis(1-(1’naphthyl) isoquinolinato-N,C2’)iridium(acetylacetonate), (1-niq)2Ir(acac), bis(1-(2’-naphthyl) isoquinolinato-N,C2’)iridium(acetylacetonate), (2-niq)2Ir(acac), and bis(1-phenyl- 5-methyl-isoquinolinato-N,C2’)iridium(acetylacetonate), (m-piq)2Ir(acac), have been synthesized and fully characterized. Electroluminescent devices with a configuration of ITO / NPB / CBP : Dopant / BCP / AlQ3 / LiF / Al were fabricated. All devices emitted in the red region with an emission ranging from 624nm to 680nm. (m-piq)2Ir(acac) shows a maximum brightness of 17164 cd/m2 at a current density of J = 300 mA/cm2 and the best luminance efficiency of 8.91 cd/A at a current density of J = 20 mA/cm2. (1-niq)2Ir(acac) exhibits pure-red emission with 1931 CIE (Commission International de L’Eclairage) chromaticity coordinates (x=0.701, y=0.273).

    　Secondly, novel red phosphorescent emitter bis(4-phenylquinazolinato-N,C2’) iridium(acetylacetonate) [(pqz)2Ir(acac)], bis(1-(1’-naphthyl)-5-methylisoquinolin ato-N,C2’)iridium(acetylacetonate) [(1-mniq)2Ir(acac)] and bis(1-(2’-naphthyl)- 5-methylisoquinolinato-N,C2’)iridium(acetylacetonate) [(2-mniq)2Ir(acac)] have been synthesized and fully characterized. The electronegative effect of (pqz)2Ir(acac) ligand shows almost the same influence as the extended π-conjugation effect of (2-mniq)2Ir(acac). Density functional theory (DFT) was applied to calculate the Kohn-Sham orbitals of HOMOs and LUMOs in the iridium complexes to illustrate the N(1) electronegative atom effect. Finally, lowest triplet state (T1) energies calculated by time-dependent DFT (TDDFT) were compared with the experimental electroluminescent data. The calculated data for the iridium complexes agreed fairly well with experimental data. Electroluminescent devices with a configuration of ITO / NPB / CBP : dopant / BCP / AlQ3 / LiF / Al were fabricated. The device using (pqz)2Ir(acac) as a dopant showed deep-red emission with 1931 CIE (Commission International de L’Eclairage) chromaticity coordinates x = 0.70, y = 0.30.

    　Thirdly, we developed a new process at high vacuum (5×10-5 torr) and high temperature (300℃) to produce meridional iridium complexes from the dimer; interestingly, mer-Ir(m-ppy)3 overthrows the concept of poor efficiency and shows excellent efficiency that is almost equal to fac-Ir(ppy)3, fac-Ir(m-ppy)3 and (ppy)2Ir(acac). In this approach, we have found that mer-Ir(m-ppy)3 in fact results in a blue shift with respect to fac-Ir(ppy)3 and produces a fairly pure green emission. Electroluminescent devices with a configuration of ITO / NPB / CBP : dopant / BCP / AlQ3 / LiF / Al were fabricated. The device using mer-Ir(m-ppy)3 as a dopant showed green emission with 1931 CIE (Commission International de L’Eclairage) chromaticity coordinates x = 0.31, y = 0.59. This result suggests us a new direction in developing novel emitter for OLEDs.

    List of tables　　　　　　　　　　　　　　　　　　　　I List of figures　　　　　　　　　　　　　　　　　　　III List of schemes　　　　　　　　　　　　　　　　　　　VII List of abbreviations　　　　　　　　　　　　　　　　VIII 1. Introduction 1.1 The development of organic light-emitting diodes　　1 1.2 The development of guest-host doped emitter system　2 1.3 The principle of electrophosphorescence　　　　　　4 1.4 The development of emitters　　　　　　　　　　　　6 1.5 Goals of this research　　　　　　　　　　　　　　11 1.5.1 Color tuning of red iridium complexes　　　　　　11 1.5.2 The electronegative effect and π-conjugation effect for iridium complexes　　　　　　　　　　　　　13 1.5.3 High efficiency mer-iridium complex　　　　　　　15 2. Experimental　　　　　　　　　　　　　　　　　　　　17 2.1 General Information　　　　　　　　　　　　　　　　17 2.2 Color tuning of red iridium complexes　　　　　　　18 2.2.1 Experimental　　　　　　　　　　　　　　　　　　18 2.2.2 OLED Fabrication and Measurement　　　　　　　　25 2.3 The electronegative effect and π-conjugation effect for iridium complexes　　　　　　　　　　　　　26 2.3.1 Experimental　　　　　　　　　　　　　　　　　　26 2.3.2 Computational methodology　　　　　　　　　　　　30 2.4 High efficiency mer-iridium complex　　　　　　　　32 2.4.1 Experimental　　　　　　　　　　　　　　　　　　32 2.4.2 OLED Fabrication and Measurement　　　　　　　　37 3. Results and discussion　　　　　　　　　　　　　　　38 3.1 Color tuning of red iridium complexes　　　　　　　38 3.1.1 Synthesis and characterization　　　　　　　　　38 3.1.2 Photophysical data　　　　　　　　　　　　　　　39 3.1.3 X-ray structural analysis　　　　　　　　　　　　43 3.1.4 Device properties　　　　　　　　　　　　　　　　45 3.2 The electronegative effect and π-conjugation effect for iridium complexes　　　　　　　　　　　　　50 3.2.1 Synthesis and characterization　　　　　　　　　50 3.2.2 Photophysical data　　　　　　　　　　　　　　　50 3.2.3 Redox chemistry　　　　　　　　　　　　　　　　　53 3.2.4 Device properties　　　　　　　　　　　　　　　　55 3.2.5 DFT calculations　　　　　　　　　　　　　　　　59 3.3 High efficiency mer-iridium complex　　　　　　　　62 3.3.1 Synthesis and characterization　　　　　　　　　62 3.3.2 Photophysical data　　　　　　　　　　　　　　　66 3.3.3 X-ray structural analysis　　　　　　　　　　　　69 3.3.4 Redox chemistry　　　　　　　　　　　　　　　　　71 3.3.5 Device properties　　　　　　　　　　　　　　　　73 4. Conclusion　　　　　　　　　　　　　　　　　　　　　77 5. References　　　　　　　　　　　　　　　　　　　　　79 6. Supporting information　　　　　　　　　　　　　　　85

    1. M. Pope, H. Kallman, P. Magnante, J. Chem. Phys., 1963, 38, 2042.
    2. C. W. Tang, US Patent 4356429, 1982.
    3. C. W. Tang, S. A. VanSlyke, C. H. Chen, Appl. Phys. Lett., 1987, 51, 913.
    4. S. A. VanSlyke, C. W. Tang, US Patent 4539507, 1985.
    5. Y. Shirota, T. Kobata, N. Noma, Chem. Lett., 1989, 7, 1145.
    6. T. Wakimoto, Y. Yonemoto, J. Funaki, M. Tsuchida, R. Murayama, H. Nakada, H. Matsumoto, S. Yamamura, M. Nomura, Synth. Met., 1997, 91, 15.
    7. P. E. Burrows, V. Khalfin, G. Gu, S. R. Forrest, Appl. Phys. Lett., 1998, 73, 435.
    8. C. W. Tang, S. A. VanSlyke, C. H. Chen, J. Appl. Phys., 1989, 65, 3610.
    9. J. Kido, “Organic Electroluminescence Materials and Displays”, , 2001.
    10. H. S. Nalwa, L. S. Rohwer, “Organic Light-Emitting Diodes”, American Scientific Publisher, 2003.
    11. B. Valeur, “Molecular Fluorescence”, WILEY-VCH, 2002.
    12. L. S. Hung, C. H. Chen, Mater. Sci. & Eng. R, 2003, 39, 143.
    13. C. Adachi, M. A. Baldo, S. R. Forrest, M. E. Thompson, J. Appl. Phys., 2001, 90, 4058.
    14. M. A. Baldo, S. Lamansky, P. E. Burrows, M. E. Thompson, S. R. Forrest, Appl. Phys. Lett., 1999, 75, 4.
    15. M. Ikai, S. Tokito, Y. Sakamoto, T. Suzuki, Y. Taga, Appl. Phys. Lett., 2001, 79, 156.
    16. V. Adamovich, J. Brooks, A. Tamayo, A. M. Alexander, P. I. Djurovich, B. W. D’Andrade, C. Adachi, S. R. Forrest, M. E. Thompson, New J. Chem., 2002, 26, 1171.
    17. W. G. Zhu, M. X. Zhu, Y. Ke, L. J. Su, M. Yuan, Y. Gao, Thin Solid Films, 2004, 446, 128.
    18. M. A. Baldo, D. F. O’Brien, Y. You, A. Shoustikov, S. Sibley, M. E. Thompson, S. R. Forrest, Nature, London, 1998, 395,151.
    19. D. F. O’Brien, M. A. Baldo, M. E. Thompson, S. R. Forrest, Appl. Phys. Lett., 1999, 74, 442.
    20. T. Sajoto, P. I. Djurovich, A. Tamayo, M. Yousufuddin, R. Bau, M. E. Thompson, Inorg. Chem., 2005, 44, 7992.
    21. C. L. Lee, R. R. Das, J. J. Kim, Chem. Mater., 2004, 16, 4642.
    22. S. T. Parker, J. D. Slinker, M. S. Lowry, M. P. Cox, S. Bernhard, G. G. Malliaras, Chem. Mater., 2005, 17, 3187.
    23. H. C. Li, P. T. Chou, Y. H. Hu, Y. M. Cheng, R. S. Liu, Organometallics, 2005, 24, 1329.
    24. D. K. Rayabarapu, B. M. J. S. Paulose, J. P. Duan, C. H. Cheng, Adv. Mater., 2005, 17, 349.
    25. J. Brooks, Y. Babayan, S. Lamansky, P. I. Djurovich, I. Tsyba, R. Bau, M. E. Thompson, Inorg. Chem., 2002, 41, 3055.
    26. P. Reveco, J. H. Medley, A. R. Garber, N. S. Bhacca, J. Selbin, Inorg. Chem., 1985, 24, 1096.
    27. P. C. Wu, J. K. Yu, Y. H. Song, Y. Chi, P. T. Chou, S. M. Peng, G. H. Lee, Organometallics, 2003, 22, 4938.
    28. Y. L. Tung, P. C. Wu, C. S. Liu, Y. Chi, J. K. Yu, Y. H. Hu, P. T. Chou, S. M. Peng, G. H. Lee, Y. Tao, A. J. Carty, C. F. Shu, F. I. Wu, Organometallics, 2004, 23, 3745.
    29. Y. L. Tung, S. W. Lee, Y. Chi, Y. T. Tao, C. H. Chien, Y. M. Cheng, P. T. Chou, S. M. Peng, C. S. Liu, J. Mater. Chem., 2005, 15, 460.
    30. S. Lamansky, P. I. Djurovich, D. Murphy, F. Abdel-Razzaq, H. E. Lee, C. Adachi, P. E. Burrows, S. R. Forrest, M. E. Thompson, J. Am. Chem. Soc., 2001, 123, 4304.
    31. K. Dedeian, J. Shi, S. Nigel, E. Forsythe, D. Morton, Inorg. Chem., 2005, 44, 4445.
    32. A. Tamayo, B. Alleyne, P. I. Djurovich, S. Lamansky, I. Tsyba, N. Ho, R. Bau, M. E. Thompson, J. Am. Chem. Soc., 2003, 125, 7377.
    33. C. H. Chen, J. Shi, K. P. Klubek, US Patent 5908581, 1999.
    34. Y. Hamada, H. Kanno, H. Fujii, T. Tsujioka, H. Takahashi, ACS Poly Millennial 2000, Abs., 2000, p167.
    35. M. Thelakkat, H. W. Schmidt, Adv. Mater., 1998, 10, 219.
    36. S. Tokito, T. Lijima, T. Tsuzuki, F. Sato, Appl. Phys. Lett., 2003, 83, 2459.
    37. F. Chen, Y. Yang, M. E. Thompson, J. Kido, Appl. Phys. Lett., 2002, 80, 2308.
    38. H. Rudmann, S. Shimada, M. F. Rubner, J. Am. Chem. Soc., 2002, 121, 4918.
    39. J. H. Kim, M. S. Liu, A. K. Y. Jen, B. Carlson L. R. Dalton, C. F. Shu, R. Dodda, Appl. Phys. Lett., 2003, 83, 776.
    40. M. A. Baldo, M. E. Thompson, S. R. Forrest, Nature, (London) 2000, 403, 750.
    41. S. Okada, H. Iwawaki, M. Furugori, J. Kamatani, S. Igawa, T. Moriyama, S. Miura. A. Tsuboyama, T. Takiguchi, H. Mizutani, 2002 SID 02 DIGEST 1360.
    42. T. Q. Chou, F. Y. Fu, Y. S. Kao, J. Am. Chem. Soc., 1948, 70, 1765.
    43. C. Lee, W. Yang, R. G. Parr, Phys. Rev. B, 1988, 37, 785.
    44. A. D. Becke, J. Chem. Phys., 1993, 98, 5648.
    45. R. E. Stratmann, G. E. Scuseria, M. J. Frisch, J. Chem. Phys., 1998, 109, 8218.
    46. R. Bauernschmitt, R. Ahlrichs, Chem. Phys. Lett., 1996, 256, 454.
    47. M. E. Casida, C. Jamorski, K. C. Casida, D. R. Salahub, J. Chem. Phys., 1998, 108, 4439.
    48. A. Rosa, E. J. Baerends, S. J. A. vanGisbergen, E. vanLenthe, J. A. Gooeneveld, J. G. Snijders, J. Am. Chem. Soc., 1999, 121, 10356.
    49. P. Boulet, H. Chermett, C. Daul, F. Gilardoni, F. Rogemond, J. Weber, G. Zuber, J. Phys. Chem. A, 2001, 105, 885.
    50. I. R. Farrell, J. van Slageren, S. Zalis, A. Vlcek, Inorg. Chim. Acta, 2001, 315, 44.
    51. A. Tsuboyama, H. Iwawaki, M. Furugori, T. Mukaide, J. Kamatani, S. Igawa, T. Moriyama, S. Miura, T. Takiguchi, S. Okada, M. Hoshino, K. Ueno, J. Am. Chem. Soc., 2003, 125, 12971.
    52. I. R. Laskar, S. F. Hsu, T. M. Chen, Polyhedron, 2005, 24, 189.
    53. S. Lamansky, P. Djurovich, D. Murphy, F. Abdel-Razzaq, R. Kwong, I. Tsyba, M. Bortz, B. Mui, R. Bau, M. E. Thompson, Inorg. Chem., 2001, 40, 1704.
    54. D. A. Walsh, J. of Med. Chem., 1978, 21, 582.
    55. M. Nonoyama, Bull. Chem. Soc. Jpn., 1974, 47, 767.
    56. B. C. Uff, B. L. Joshi, J. Chem. Soc. Perkin Trans., 1986, 1, 2295.
    57. M. J. Frisch, et al., Gaussian 98 Revision A.11, Gaussian, Inc., Pittsburgh, PA, 2001.
    58. P. J. Hay, W. R. Wadt, J. Chem. Phys., 1985, 82, 270.
    59. P. J. Hay, J. Phys. Chem. A, 2002, 106, 1634.
    60. M. Polson, S. Fracasso, V. Bertolasi, M. Ravaglia, F. Scandola, Inorg. Chem., 2004, 43, 1950.
    61. The (piq)2Ir(acac) complex was described in a recent paper by Y. J. Su and co-workers. The device based on this complex gave a ηext = 8.46% at J = 20 mA/cm2. In this paper, we use the (piq)2Ir(acac) as standard and (m-piq)2Ir(acac) shows better luminance efficiency and brightness. We predicted that (m-piq)2Ir(acac) must exhibited the better ηext than (piq)2Ir(acac). See: Y. J. Su, H. L. Huang, C. L. Li, C. H. Chien, Y. T. Tao, P. T. Chou, S. Datta and R. S. Liu, Adv. Mater., 2003, 15, 884.
    62. M. G. Colombo, A. Hauser, H. U. Gudel, Inorg. Chem., 1993, 32, 3088.
    63. H. M. Koepp, H. Wendt, H. Strehlow, Z. Electrochem., 1960, 64, 483.
    64. P. E. Burrows, Z. Shen, V. Bulovic, D. M. McCarty, S. R. Forrest, J. Appl. Phys., 1996, 79, 7991.
    65. M. E. Thompson, P. Djurovich, S. Lamansky, D. Murphy, R. Kwong, F. Abdel-Razzaq, S. R. Forrest, M. A. Baldo, P. E. Burrows, US Patent 0034656 A1, 2002.

    下載圖示 校內：2007-04-25公開
    校外：2007-04-25公開
    QR CODE