Phosphorescent organic light-emitting devices: Working principle and iridium based emitter materials

International Journal of Molecular Sciences

Volumn 9, Issue 8, 2008, Pages 1527-1547

  Kappaun, Stefan ^a   Slugovc, Christian ^b   List, Emil J W ^a,c  

^a NanoTecCenter Weiz Forschungsgesellschaft mbH   (Austria)

^b GRAZ UNIVERSITY OF TECHNOLOGY   (Austria)

^c GRAZ UNIVERSITY OF TECHNOLOGY   (Austria)

Author keywords

Electroluminescence; Fluorescence; Organic light emitting devices (OLEDs); Phosphorescence; Phosphorescent polymers

Indexed keywords

IRIDIUM COMPLEX; POLYMER;

DISPLAY SYSTEM; EQUIPMENT DESIGN; FLUORESCENCE; LIGHT EMITTING DIODE; LIQUID CRYSTAL; LUMINESCENCE; ORGANIC LIGHT EMITTING DEVICE; PHOSPHORESCENCE; PHOTOCHEMISTRY; PHYSICAL CHEMISTRY; POLYMERIZATION; QUANTUM MECHANICS; REVIEW; SYNTHESIS;

EID: 50849111473     PISSN: None     EISSN: 14220067     Source Type: Journal    
DOI: 10.3390/ijms9081527     Document Type: Review

References (102)

1. Pope, M.; Kallmann, H.; Magnante, P. Electroluminescence in Organic Crystals. J. Chem. Phys. 1963, 38, 2042-2043.
2. Vardeny, Z.V.; Heeger, A.J.; Dodabalapur, A. Fundamental Research Needs in Organic Electronic Materials. Synth. Met. 2005, 148, 1-3.
3. Tang, C.W.; VanSlyke, S.A. Organic Electroluminescent Diodes. Appl. Phys. Lett. 1987, 51, 913-915.
4. Haskal, E.I.; Büchel, M.; Duineveld, P.C.; Sempel, A.; van de Weijer, P. Passive-Matrix Polymer Light-Emitting Displays. MRS Bull. 2002, 864-869.
5. Nuyken, O.; Jungermann, S.; Wiederhirn, V.; Bacher, E.; Meerholz, K. Modern Trends in Organic Light-Emitting Devices (OLEDs). Monatsh. Chem. 2006, 137, 811-824.
6. Kido, J.; Matsumoto, T. Bright Organic Electroluminescent Devices Having a Metal-doped Electron-injecting Layer. Appl. Phys. Lett. 1998, 73, 2866-2868.
7. Walzer, K.; Maennig, B.; Pfeiffer, M.; Leo, K. Highly Efficient Organic Devices Based on Electrically Doped Transport Layers. Chem. Rev. 2007, 107, 1233-1271.
8. Sović, T.; Kappaun, S.; Koppitz, A.; Zojer, E.; Saf, R.; Bartl, K.; Fodor-Csorba, K.; Vajda, A.; Diele, S.; Pelzl, G.; Slugovc, C.; Stelzer, F. Main-Chain Liquid Crystalline Polymers Based on Bis-Etherified 9,9-Dihexyl-2,7-bis(40-hydroxy-1,10-biphen-4-yl)fluorenes. Macromol. Chem. Phys. 2007, 208, 1458-1468.
9. Waser, R., Ed. Nanoelectronics and Information Technology-Advanced Electronic Materials and Novel Devices; Wiley-VCH: Weinheim, 2003; p. 917.
10. Blom, P.W.M.; Tanase, C.; de Leeuw, D.M.; Coehoorn, R. Thickness Scaling of the Spacecharge-limited Current in poly(p-phenylene vinylene). Appl. Phys. Lett. 2005, 86, 092105-092105-3.
11. Wohlgenannt, M.; Tandon, K.; Mazumdar, S.; Ramasesha, S.; Vardeny, Z.V. Formation Crosssections of Singlet and Triplet Excitons in π-conjugated Polymers. Nature 2001, 409, 494-497.
12. Köhler, A.; Wilson, J.S.; Friend, R.H. Fluorescence and Phosphorescence in Organic Materials. Adv. Mater. 2002, 14, 701-707.
13. Shuai, Z.; Beljonne, D.; Silbey, R.J.; Brédas, J.L. Singlet and Triplet Exciton Formation Rates in Conjugated Polymer Light-Emitting Diodes. Phys. Rev. Lett. 2000, 84, 131-134.
14. Yang, X.; Neher, D. Polymer Electrophosphorescence Devices. In Organic Light-Emitting Devices; Müllen, K., Scherf, U., Eds.; Wiley-VCH: Weinheim, 2006; p. 333.
15. Kido, J.; Kimura, M.; Nagai, K. Multilayer White Light-Emitting Organic Electroluminescent Device. Science 1995, 267, 1332-1334.
16. Campbell, I.H.; Crone, B.K.; Smith, D.L. Physics of Organic Light-Emitting Diodes. In Semiconducting Polymers; Hadziioannou, G., Malliaras, G.G., Eds.; Wiley-VCH: Weinheim, 2007; p. 421.
17. Sheats, J.R. Manufacturing and Commercialization Issues in Organic Electronics. J. Mater. Res. 2004, 19, 1974-1989.
18. Gong, X.; Moses, D.; Heeger, A.J. Polymer-Based Light-Emitting Diodes (PLEDs) and Displays-Fabrication from Arrays of PLEDs. In Semiconducting Polymers; Hadziioannou, G., Malliaras, G.G., Eds.; Wiley-VCH: Weinheim, 2007; p. 151.
19. Fung, M.-K.; Lee, C.-S.; Lee, S.-T. Metal/Polymer Interface Studies for Organic Light-Emitting Devices. In Organic Light-Emitting Devices; Müllen, K., Scherf, U., Eds.; Wiley-VCH: Weinheim, 2006; p. 181.
20. Burroughes, J.H.; Bradley, D.D.C.; Brown, A.R.; Marks, R.N.; Mackay, K.; Friend, R.H.; Burns, P.L.; Holmes, A.B. Light-emitting Diodes Based on Conjugated Polymers. Nature 1990, 347, 539-541.
21. Lu, J.; Jin, Y.; Ding, J.; Tao, Y.; Day, M. High-efficiency Multilayer Polymeric Blue Light-emitting Diodes Using Boronate Esters as Cross-linking Linkages. J. Mater. Chem. 2006, 16, 593-601.
22. Lim, S.C.; Kim, S.H.; Chu, H.Y.; Lee, J.H.; Lee, J.-I.; Oh, J.Y.; Kim, D.; Zyung, T. New Method of Driving an OLED with an OTFT. Synth. Met. 2005, 151, 197-201.
23. Shao, Y.; Yang, Y. Organic Solid Solutions: Formation and Applications in Organic Light-Emitting Diodes. Adv. Funct. Mater. 2005, 15, 1781-1786.
24. Smith, L.H.; Wasey, J.A.E.; Samuel, I.D.W.; Barnes, W.L. Light Out-Coupling Efficiencies of Organic Light-Emitting Diode Structures and the Effect of Photoluminescence Quantum Yield. Adv. Funct. Mater. 2005, 15, 1839-1844.
25. Yersin, H. Triplet Emitters for OLED Applications. Mechanisms of Exciton Trapping and Control of Emission Properties. Top. Curr. Chem. 2004, 241, 1-26.
26. Meerholz, K.; Müller, C.-D.; Nuyken, O. Crosslinkable Organic Semiconductors for Use in Organic Light-Emitting Diodes (OLEDs). In Organic Light-Emitting Devices; Müllen, K., Scherf, U., Eds.; Wiley-VCH: Weinheim, 2006; p. 293.
27. Baldo, M.A.; O'Brien, D.F.; You, Y.; Shoustikov, A.; Sibley, S.; Thompson, M.E.; Forrest, S.R. Highly Efficient Phosphorescent Emission from Organic Electroluminescent Devices. Nature 1998, 395, 151-154.
28. Evans, R.C.; Douglas, P.; Winscom, C.J. Coordination Complexes Exhibiting Room-temperature Phosphorescence: Evaluation of Their Suitability as Triplet Emitters in Organic Light Emitting Diodes. Coord. Chem. Rev. 2006, 250, 2093-2126.
29. Tsuboi, T.; Aljaroudi, N. Electronic Relaxation Processes in the T1 State of Phosphorescent factris(2-phenylpyridine) Iridium Molecule in 4,4′-N,N′-dicarbazole-biphenyl Host. Jpn. J. Appl. Phys. 2008, 47, 1266-1270.
30. Hertel, D.; Müller, C.D.; Meerholz, K. Organische Leuchtdioden: Bilderzeugung. Chem. Unserer Zeit 2005, 39, 336-347.
31. Wang, Y.; Herron, N.; Grushin, V.V.; LeCloux, D.; Petrov, V. Highly Efficient Electroluminescent Materials Based on Fluorinated Organometallic Iridium Compounds. Appl. Phys. Lett. 2001, 79, 449-451.
32. Wong, K.-T.; Chen, Y.-M.; Lin, Y.-T.; Su, H.-C.; Wu, C.-C. Nonconjugated Hybrid of Carbazole and Fluorene: A Novel Host Material for Highly Efficient Green and Red Phosphorescent OLEDs. Org. Lett. 2005, 7, 5361-5364.
33. van Dijken, A.; Bastiaansen, J.J.A.M.; Kiggen, N.M.M.; Langeveld, B.M.W.; Rothe, C.; Monkman, A.; Bach, I.; Stössel, P.; Brunner, K. Carbazole Compounds as Host Materials for Triplet Emitters in Organic Light-Emitting Diodes: Polymer Hosts for High-Efficiency Light-Emitting Diodes. J. Am. Chem. Soc. 2004, 126, 7718-7727.
34. Zhu, W.; Mo, Y.; Yuan, M.; Yang, W.; Cao, Y. Highly Efficient Electrophosphorescent Devices Based on Conjugated Polymers Doped with Iridium Complexes. Appl. Phys. Lett. 2002, 80, 2045-2047.
35. Brunner, K.; van Dijken, A.; Börner, H.; Bastiaansen, J.J.A.M.; Kiggen, N.M.M.; Langeveld, B.M.W. Carbazole Compounds as Host Materials for Triplet Emitters in Organic Light-Emitting Diodes: Tuning the HOMO Level without Influencing the Triplet Energy in Small Molecules. J. Am. Chem. Soc. 2004, 126, 6035-6042.
36. Chen, Y.-C.; Huang, G.-S.; Hsiao, C.-C.; Chen, S.-A. High Triplet Energy Polymer as Host for Electrophosphorescence with High Efficiency. J. Am. Chem. Soc. 2006, 128, 8549-8558.
37. King, S.M.; Al-Attar, H.A.; Evans, R.J.; Congreve, A.; Beeby, A.; Monkman, A.P. The Use of Substituted Iridium Complexes in Doped Polymer Electrophosphorescent Devices: The Influence of Triplet Transfer and Other Factors on Enhancing Device Performance. Adv. Funct. Mater. 2006, 16, 1043-1050.
38. Vecchi, P.A.; Padmaperuma, A.B.; Qiao, H.; Sapochak, L.S.; Burrows, P.E.A Dibenzofuran-Based Host Material for Blue Electrophosphorescence. Org. Lett. 2006, 8, 4211-4214.
39. Lin, C.-H.; Chang, Y.-T.; Li, C.-S.; Liu, C.-H.; Duan, J.-P. Bis(arylquinoxalinyl)carbazole Derivatives as Saturated Blue Emitters for Electroluminescent Devices. Synth. Met. 2006, 156, 671-676.
40. Tsai, M.-H.; Lin, H.-W.; Su, H.-C.; Ke, T.-H.; Wu, C.-c.; Fang, F.-C.; Liao, Y.-L.; Wong, K.-T.; Wu, C.-I Highly Efficient Organic Blue Electrophosphorescent Devices Based on 3,6-Bis(triphenylsilyl)carbazole as the Host Material. Adv. Mater. 2006, 18, 1216-1220.
41. Padmaperuma, A.B.; Sapochak, L.S.; Burrows, P.E. New Charge Transporting Host Material for Short Wavelength Organic Electrophosphorescence: 2,7-Bis(diphenylphosphineoxide)-9,9-dimethylfluorene. Chem. Mater. 2006, 18, 2389-2396.
42. Gong, X.; Ostrowski, J.C.; Moses, D.; Bazan, G.C.; Heeger, A.J. High-performance Polymer-based Electrophosphorescent Light-emitting Diodes. J. Polym. Sci., Part B: Polym. Phys. 2003, 41, 2691-2705.
43. Li, Y.; Ding, J.; Day, M.; Tao, Y.; Lu, J.; D'iorio, M. Synthesis and Properties of Random and Alternating Fluorene/Carbazole Copolymers for Use in Blue Light-Emitting Devices. Chem. Mater. 2004, 16, 2165-2173.
44. Diaz, J.L.; Dobarro, A.; Villacampa, B.; Velasco, D. Structure and Optical Properties of 2,3,7,9-Polysubstituted Carbazole Derivatives. Experimental and Theoretical Studies. Chem. Mater. 2001, 13, 2528-2536.
45. Grigalevicius, S. 3,6(2,7),9-Substituted carbazoles as Electroactive Amorphous Materials for Optoelectronics. Synth. Met. 2006, 156, 1-12.
46. Wong, K.-T.; Liao, Y.-L.; Lin, Y.-T.; Su, H.-C.; Wu, C.-c. Nonconjugated Hybrid of Carbazole and Fluorene: A Novel Host Material for Highly Efficient Green and Red Phosphorescent OLEDs. Org. Lett. 2005, 7, 5131-5364.
47. Wu, F.-I.; Shih, P.-I; Yuan, M.-C.; Dixit, A.K.; Shu, C.-F.; Chung, Z.-M.; Diau, E.W.-G. Novel Distyrylcarbazole Derivatives as Hole-transporting Blue Emitters for Electroluminescent Devices. J. Mater. Chem. 2005, 15, 4753-4760.
48. Cha, S.W.; Joo, S.-H.; Jeong, M.-Y.; Jin, J.-I. Balancing Charge Carrier Mobility by Constructing Chemical Structures to Contain both Hole- and Electron-transporting Moieties in Electroluminescent Organic Compounds. Synth. Met. 2005, 150, 309-316.
49. Kremser, G.; Hofmann, O.T.; Sax, S.; Kappaun, S.; List, E.J.W.; Zojer, E.; Slugovc, C. Synthesis and Photophysical Properties of 3,6-Diphenyl-9-hexyl- 9H-carbazole Derivatives Bearing Electron Withdrawing Groups. Monatsh. Chem. 2008, 139, 223-231.
50. 2)-2- phenylpyridine Platinum Complexes: The Use of bis(pyrazolyl)borates as Ancillary Ligands. Inorg. Chim. Acta 2007, 360, 2767-2777.
51. Niedermair, F.; Kwon, O.; Zojer, K.; Kappaun, S.; Trimmel, G.; Mereiter, K.; Slugovc, C. Heteroleptic Platinum(II) Complexes of 8-Quinolinolates Bearing Electron Withdrawing Groups in 5 Position. Dalton Trans. 2008, 4006-4014.
52. Dixon, I.M.; Collin, J.P.; Sauvage, J.P.; Flamigni, L.; Encinas, S.; Barigelletti, F. A Family of Luminescent Coordination Compounds: Iridium(III) Polyimine Complexes. Chem. Soc. Rev. 2000, 29, 385-391.
53. Lowry, M.S.; Bernhard, S. Synthetically Tailored Excited States: Phosphorescent, Cyclometalated Iridium(III) Complexes and Their Applications. Chem. Eur. J. 2006, 12, 7970-7977.
54. Goushi, K.; Kwong, R.; Brown, J.J.; Sasabe, H.; Adachi, C. Triplet Exciton Confinement and Unconfinement by Adjacent Hole-transport Layers. J. Appl. Phys. 2004, 95, 7798-7802.
55. Holder, E.; Langeveld, B.M.W.; Schubert, U.S. New Trends in the Use of Transition Metal-Ligand Complexes for Applications in Electroluminescent Devices. Adv. Mater. 2005, 17, 1109-1121.
56. Slinker, J.D.; Gorodetsky, A.A.; Lowry, M.S.; Wang, J.; Parker, S.; Rohl, R.; Bernhard, S.; Malliaras, G.G. Efficient Yellow Electroluminescence from a Single Layer of a Cyclometalated Iridium Complex. J. Am. Chem. Soc. 2004, 126, 2763-2767.
57. Nonoyama, M. Benzo[h]quinolin-10-yl-N Iridium(III) Complexes Bull. Chem. Soc. Jpn. 1974, 47, 767-768.
58. Ionkin, A.S.; Marshall, W.J.; Fish, B.M. Synthesis and Structural Characterization of a Series of Novel Polyaromatic Ligands Containing Pyrene and Related Biscyclometalated Iridium(III) Complexes. Organometallics 2006, 25, 1461-1471.
59. King, K.A.; Spellane, P.J.; Watts, R.J. Excited-state Properties of a Triply Ortho-metalated Iridium(III) Complex. J. Am. Chem. Soc. 1985, 107, 1431-1432.
60. Ionkin, A.S.; Marshall, W.J.; Roe, D.C.; Wang, Y. Synthesis, Structural Characterization and the First Electroluminescent Properties of Tris- and Bis-cycloiridiated Complexes of Sterically Hindered Electron-poor 2-(3,5-bis(trifluoromethyl)phenyl)-4-trifluoromethylpyridine. Dalton Trans. 2006, 2468-2478.
61. Tamayo, A.B.; Alleyne, B.D.; Djurovich, P.I.; Lamansky, S.; Tsyba, I.; Ho, N.N.; Bau, R.; Thompson, M.E. Synthesis and Characterization of Facial and Meridional Tris-cyclometalated Iridium(III) Complexes. J. Am. Chem. Soc. 2003, 125, 7377-7387.
62. Huo, S.; Deaton, J.C.; Rajeswaran, M.; Lenhart, W.C. Highly Efficient, Selective, and General Method for the Preparation of Meridional Homo- and Heteroleptic Tris-cyclometalated Iridium Complexes. Inorg. Chem. 2006, 45, 3155-3157.
63. Dedeian, K.; Shi, J.; Shepard, N.; Forsythe, E.; Morton, D. C. Photophysical and Electrochemical Properties of Heteroleptic Tris-Cyclometalated Iridium(III) Complexes. Inorg. Chem. 2005, 44, 4445-4447.
64. Kappaun, S.; Rentenberger, S.; Pogantsch, A.; Zojer, E.; Mereiter, K.; Trimmel, G.; Saf, R.; Möller, K.C.; Stelzer, F.; Slugovc, C. Organoboron Quinolinolates with Extended Conjugated Chromophores: Synthesis, Structure, and Electronic and Electroluminescent Properties. Chem. Mater. 2006, 18, 3539-3547.
65. You, Y.; Park, S.Y. Inter-Ligand Energy Transfer and Related Emission Change in the Cyclometalated Heteroleptic Iridium Complex: Facile and Efficient Color Tuning over the Whole Visible Range by the Ancillary Ligand Structure. J. Am. Chem. Soc. 2005, 127, 12438-12439.
66. Kappaun, S.; Sax, S.; Eder, S.; Möller, K.C.; Waich, K.; Niedermair, F.; Saf, R.; Mereiter, K.; Jacob, J.; Müllen, K.; List, E.J.W.; Slugovc, C. 8-Quinolinolates as Ligands for Luminescent Cyclometalated Iridium Complexes. Chem. Mater. 2007, 19, 1209-1211.
67. Kappaun, S.; Eder, S.; Sax, S.; Mereiter, K.; List, E.J.W.; Slugovc, C. Organoiridium Quinolinolate Complexes: Synthesis, Structures, Thermal Stabilities and Photophysical Properties. Eur. J. Inorg. Chem. 2007, 4207-4215.
68. Lamansky, S.; Djurovic, P.; Murphy, D.; Abdel-Razzaq, F.; Kwong, R.; Tsyba, I.; Bortz, M.; Mui, B.; Bau, R.; Thompson, M.E. Synthesis and Characterization of Phosphorescent Cyclometalated Iridium Complexes. Inorg. Chem. 2001, 40, 1704-1711.
69. Lamansky, S.; Djurovich, P.; Murphy, D.; Abdel-Razzaq, F.; Lee, H.-E.; Adachi, C.; Burrows, P.E.; Forrest, S.R.; Thompson, M.E. Highly Phosphorescent Bis-Cyclometalated Iridium Complexes: Synthesis, Photophysical Characterization, and Use in Organic Light Emitting Diodes. J. Am. Chem. Soc. 2001, 123, 4304-4312.
70. Hsu, N.-M.; Li, W.-R. Accelerated Discovery of Red-Phosphorescent Emitters through Combinatorial Organometallic Synthesis and Screening. Angew. Chem. 2006, 118, 4244-4248.
71. Yang, C.-H.; Li, S.-W.; Chi, Y.; Cheng, Y.-M.; Yeh, Y.-S.; Chou, P.-T.; Lee, G.-H.; Wang, C.-H.; Shu, C.-F. Heteroleptic Cyclometalated Iridium(III) Complexes Displaying Blue Phosphorescence in Solution and Solid State at Room Temperature. Inorg. Chem. 2005, 44, 7770-7780.
72. Sajoto, T.; Djurovich, P.I.; Tamayo, A.; Yousufuddin, M.; Bau, R.; Thompson, M.E. Blue and Near-UV Phosphorescence from Iridium Complexes with Cyclometalated Pyrazolyl or N-Heterocyclic Carbene Ligands. Inorg. Chem. 2005, 44, 7992-8003.
73. Mak, C.S.K.; Hayer, A.; Pascu, S.I.; Watkins, S.E.; Holmes, A.B.; Köhler, A.; Friend, R.H. Blue-to-green Electrophosphorescence of Iridium-based Cyclometalated Materials. Chem. Commun. 2005, 4708-4710.
74. Jang, H.; Shin, C.H.; Kim, N.G.; Hwang, K.Y.; Do, Y. New Phosphorescent ppy-based Iridium Complexes Containing Electron-withdrawing Groups. Synth. Met. 2005, 154, 157-160.
75. Ragni, R.; Plummer, E.A.; Brunner, K.; Hofstraat, J.W.; Babudri, F.; Farinola, G.M.; Naso, F.; De Cola, L. Blue Emitting Iridium Complexes: Synthesis, Photophysics and Phosphorescent Devices. J. Mater. Chem. 2006, 16, 1161-1170.
76. Chin, C.S.; Eum, M.-S.; Kim, S.y.; Kim, C.; Kang, S.K. Blue-Light-Emitting Complexes: Cationic (2-Phenylpyridinato)iridium(III) Complexes with Strong-Field Ancillary Ligands. Eur. J. Inorg. Chem. 2007, 372-375.
77. Lo, S.-C.; Shipley, C.P.; Bera, R.N.; Harding, R.E.; Cowley, A.R.; Burn, P.L.; Samuel, I.D.W. Blue Phosphorescence from Iridium(III) Complexes at Room Temperature. Chem. Mater. 2006, 18, 5119-5129.
78. Chou, P.-T.; Chi, Y. Phosphorescent Dyes for Organic Light-Emitting Diodes. Chem. Eur. J. 2007, 13, 380-395.
79. Li, J.; Djurovich, P.I.; Alleyne, B.D.; Yousufuddin, M.; Ho, N.N.; Thomas, J.C.; Peters, J.C.; Bau, R.; Thompson, M.E. Synthetic Control of Excited-State Properties in Cyclometalated Ir(III) Complexes Using Ancillary Ligands. Inorg. Chem. 2005, 44, 1713-1727.
80. Liu, T.; Xia, B.-H.; Zhou, X.; Zhang, H.-X.; Pan, Q.-J.; Gao, J.-S. Theoretical Studies on Structures and Spectroscopic Properties of Bis-Cyclometalated Iridium Complexes. Organometallics 2007, 26, 143-149.
81. Kwon, T.-H.; Cho, H.S.; Kim, M.K.; Kim, J.-W.; Kim, J.-J.; Lee, K.H.; Park, S.J.; Shin, I.-S.; Kim, H.; Shin, D.M.; Chung, Y.K.; Hong, J.-I. Color Tuning of Cyclometalated Iridium Complexes through Modification of Phenylpyrazole Derivatives and Ancillary Ligand Based on ab Initio Calculations. Organometallics 2005, 24, 1578-1585.
82. Bansal, A.K.; Holzer, W.; Penzkofer, A.; Tsuboi, T. Absorption and Emission Spectroscopic Characterization of Platinum-octaethyl-porphyrin (PtOEP). Chem. Phys. 2006, 330, 118-129.
83. Holzer, W.; Penzkofer, A.; Tsuboi, T. Absorption and Emission Spectroscopic Characterization of Ir(ppy)3. Chem. Phys. 2005, 308, 93-102.
84. Koga, Y.; Ueno, K.; Matsubara, K. New Preparative Procedure for Photoluminescent Metallopolymers Having a Biphenyl-2,2′-diyl Iridium(III) Unit Bound to a Phosphine Copolymer Ligand. J. Polym. Sci., Part A: Polym. Chem. 2006, 44, 4204-4213.
85. You, Y.; Kim, S.H.; Jung, H.K.; Park, S.Y. Blue Electrophosphorescence from Iridium Complex Covalently Bonded to the Poly(9-dodecyl-3-vinylcarbazole): Suppressed Phase Segregation and Enhanced Energy Transfer. Macromolecules 2006, 39, 349-356.
86. Jiang, J.; Jiang, C.; Yang, W.; Zhen, H.; Huang, F.; Cao, Y. High-Efficiency Electrophosphorescent Fluorene-alt-carbazole Copolymers N-Grafted with Cyclometalated Ir Complexes. Macromolecules 2005, 38, 4072-4080.
87. Carlise, J.R.; Wang, X.-Y.; Weck, M. Phosphorescent Side-Chain Functionalized Poly(norbornene)s Containing Iridium Complexes. Macromolecules 2005, 38, 9000-9008.
88. Wang, X.-Y.; Prabhu, R.N.; Schmehl, R.H.; Weck, M. Polymer-Based Tris(2-phenylpyridine)iridium Complexes. Macromolecules 2006, 39, 3140-3146.
89. Chen, X.; Liao, J.-L.; Liang, Y.; Ahmed, M.O.; Tseng, H.-E.; Chen, S.-A. High-Efficiency Red-Light Emission from Polyfluorenes Grafted with Cyclometalated Iridium Complexes and Charge Transport Moiety. J. Am. Chem. Soc. 2003, 125, 636-637.
90. Deng, L.; Furuta, P.T.; Garon, S.; Li, J.; Kavulak, D.; Thompson, M.E.; Frechet, J.M.J. Living Radical Polymerization of Bipolar Transport Materials for Highly Efficient Light Emitting Diodes. Chem. Mater. 2006, 18, 386-395.
91. Wang, X.-Y.; Kimyonok, A.; Weck, M. Functionalization of Polymers with Phosphorescent Iridium Complexes via Click Chemistry. Chem. Commun. 2006, 3933-3925.
92. Kimyonok, A.; Weck, M. Poly(cyclooctene)s with Pendant Fluorescent and Phosphorescent Metal Complexes. Macromol. Rapid Commun. 2007, 28, 152-157.
93. Zhang, K.; Chen, Z.; Yang, C.; Gong, S.; Qin, J.; Cao, Y. Saturated Red-Emitting Electrophosphorescent Polymers with Iridium Coordinating to β-Diketonate Units in the Main Chain. Macromol. Rapid Commun. 2006, 27, 1926-1931.
94. Evans, N.R.; Devi, L.S.; Mak, C.S.K.; Watkins, S.E.; Pascu, S.I.; Köhler, A.; Friend, R.H.; Williams, C.K.; Holmes, A.B. Triplet Energy Back Transfer in Conjugated Polymers with Pendant Phosphorescent Iridium Complexes. J. Am. Chem. Soc. 2006, 128, 6647-6656.
95. Kimyonok, A.; Domercq, B.; Haldi, A.; Cho, J.-Y.; Carlise, J.R.; Wang, X.-Y.; Hayden, L.E.; Jones, S.C.; Barlow, S.; Marder, S.R.; Kippelen, B.; Weck, M. Norbornene-Based Copolymers with Iridium Complexes and Bis(carbazolyl) fluorene Groups in Their Side-Chains and Their Use in Light-Emitting Diodes. Chem. Mater. 2007, 19, 5602-5608.
96. Rehmann, N.; Ulbricht, C.; Köhnen, A.; Zacharias, P.; Gather, M.C.; Hertel, D.; Holder, E.; Meerholz, K.; Schubert, U. Advanced Device Architecture for Highly Efficient Organic Light-Emitting Diodes with an Orange-Emitting Crosslinkable Iridium(III) Complex. Adv. Mater. 2008, 20, 129-133.
97. Yang, W.; Zhen, H.Y.; Jiang, C.Y.; Su, L.J.; Jiang, J.X.; Shi, H.H.; Cao, Y. Synthesis of Electrophosphorescent Polymers Based on Para-phenylenes with Iridium Complexes. Synth. Met. 2005, 153, 189-192.
98. Zhen, H.; Jiang, C.; Yang, W.; Jiang, J.; Huang, F.; Cao, Y. Synthesis and Properties of Electrophosphorescent Chelating Polymers with Iridium Complexes in the Conjugated Backbone. Chem. Eur. J. 2005, 11, 5007-5016.
99. Zhen, H.; Luo, C.; Yang, W.; Song, W.; Du, B.; Jiang, J.; Jiang, C.; Zhang, Y.; Cao, Y. Electrophosphorescent Chelating Copolymers Based on Linkage Isomers of Naphthylpyridine-Iridium Complexes with Fluorene. Macromolecules 2006, 39, 1693-1700.
100. Liu, S.-J.; Zhao, Q.; Chen, R.-F.; Deng, Y.; Fan, Q.-L.; Li, F.-Y.; Wang, L.-H.; Huang, C.-H.; Huang, W. π-Conjugated Chelating Polymers with Charged Iridium Complexes in the Backbones: Synthesis, Characterization, Energy Transfer, and Electrochemical Properties. Chem. Eur. J. 2006, 12, 4351-4361.
101. Zhuang, W.; Zhang, Y.; Hou, Q.; Wang, L.; Cao, Y. High-Efficiency, Electrophosphorescent Polymers with Porphyrin-Platinum Complexes in the Conjugated Backbone: Synthesis and Device Performance. J. Polym. Sci., Part A: Polym. Chem. 2006, 44, 4174-4186.
102. Kappaun, S.; Eder, S.; Sax, S.; Saf, R.; Mereiter, K.; List, E.J.W.; Slugovc, C. WPLEDs Prepared from Main-chain Fluorene-iridium(III) Polymers. J. Mater. Chem. 2006, 16, 4389-4392.