Ambipolar Conductive 2,7‐Carbazole Derivatives for Electroluminescent Devices

A series of 2,7‐disubstituted carbazole (2,7‐carb) derivatives incorporating arylamines at the 2 and 7 positions are synthesized via palladium‐catalyzed C–N or C–C bond formation. These compounds possess glass transition temperatures ranging from 87 to 217 °C and exhibit good thermal stabilities, with thermal decomposition temperatures ranging from 388 to 480 °C. They are fluorescent and emit in the purple‐blue to orange region. Two types of organic light emitting diodes (OLEDs) were constructed from these compounds: (I) indium tin oxide (ITO)/2,7‐carb (40 nm)/1,3,5‐tris(N‐phenylbenzimidazol‐2‐yl)benzene (TPBI, 40 nm)/Mg:Ag; and (II) ITO/2,7‐carb (40 nm)/tris(8‐hydroxyquinoline) aluminum (Alq3, 40 nm)/Mg:Ag. In type I devices, the 2,7‐disubstituted carbazoles function as both hole‐transporting and emitting material. In type II devices, light is emitted from either the 2,7‐disubstituted carbazole layer or Alq3. The devices appear to have a better performance compared to devices fabricated with their 3,6‐disubstituted carbazole congeners. Some of the new compounds exhibit ambipolar conductive behavior, with hole and electron mobilities up to 10–4 cm2 V–1 s–1.

[1]  W. D. Gill.  Drift mobilities in amorphous charge‐transfer complexes of trinitrofluorenone and poly‐n‐vinylcarbazole , 1972 .

[2]  Guilford Jones,et al.  Solvent effects on emission yield and lifetime for coumarin laser dyes. Requirements for a rotatory decay mechanism , 1983 .

[3]  C. Tang,et al.  Organic Electroluminescent Diodes , 1987 .

[4]  R. N. Marks,et al.  Light-emitting diodes based on conjugated polymers , 1990, Nature.

[5]  L. B. Schein,et al.  Comparison of charge transport models in molecularly doped polymers , 1992 .

[6]  A. Miura,et al.  Molecular design for nonpolymeric organic dye glasses with thermal stability : relations between thermodynamic parameters and amorphous properties , 1993 .

[7]  Borsenberger.  Organic Photoreceptors for Imaging Systems , 2018 .

[8]  K. Naito.  Quantitative Relations between Glass Transition Temperatures and Thermodynamic Parameters for Various Materials: Molecular Design for Nonpolymeric Organic Dye Glasses with Thermal Stability , 1994 .

[9]  H. Bässler.  Hopping conduction in polymers , 1994 .

[10]  Rainer F. Mahrt,et al.  Efficient two layer leds on a polymer blend basis , 1995 .

[11]  Josef Salbeck,et al.  Low molecular organic glasses for blue electroluminescence , 1997 .

[12]  J. Hartwig.  Palladium-Catalyzed Amination of Aryl Halides: Mechanism and Rational Catalyst Design , 1997 .

[13]  Synthesis and Luminescent Properties of 2-Phenyl-5-{4[2-(6-substituent-2H-benz[de]isoquinoline-1,3(2H)-dione-2-yl) polymethano-]amino-}phenyl-1,3,4-oxadiazole , 1997 .

[14]  Stephen R. Forrest,et al.  Thermally induced failure mechanisms of organic light emitting device structures probed by X-ray specular reflectivity , 1997 .

[15]  Mark E. Thompson,et al.  Asymmetric Triaryldiamines as Thermally Stable Hole Transporting Layers for Organic Light-Emitting Devices , 1998 .

[16]  Jianmin Shi,et al.  Metal chelates as emitting materials for organic electroluminescence , 1998 .

[17]  J. Hartwig.  Synthesis, Structure, and Reactivity of a Palladium Hydrazonato Complex: A New Type of Reductive Elimination Reaction To Form C-N Bonds and Catalytic Arylation of Benzophenone Hydrazone. , 1998, Angewandte Chemie.

[18]  M. Nishiyama,et al.  Synthesis of N-arylpiperazines from aryl halides and piperazine under a palladium tri-tert-butylphosphine catalyst , 1998 .

[19]  H. Tian,et al.  Luminescent properties of copolymeric dyad compounds containing 1,8-naphthalimide and 1,3,4-oxadiazole , 1998 .

[20]  Stephen R. Forrest,et al.  Hole Transporting Materials with High Glass Transition Temperatures for Use in Organic Light-Emitting Devices , 1998 .

[21]  A. Jen,et al.  Triarylamine-Containing Poly(perfluorocyclobutane) as Hole-Transporting Material for Polymer Light-Emitting Diodes , 2000 .

[22]  M. Thompson,et al.  Organic Light-emitting Devices Based on Phosphorescent Hosts and Dyes , 2000 .

[23]  Tetsuya Noda,et al.  A Novel Class of Emitting Amorphous Molecular Materials as Bipolar Radical Formants: 2-{4-[Bis(4-methylphenyl)amino]phenyl}- 5-(dimesitylboryl)thiophene and 2-{4-[Bis(9,9-dimethylfluorenyl)amino]phenyl}- 5-(dimesitylboryl)thiophene , 2000 .

[24]  Y. Shirota.  Organic materials for electronic and optoelectronic devices , 2000 .

[25]  Ullrich Mitschke,et al.  The electroluminescence of organic materials , 2000 .

[26]  J. Fréchet,et al.  Dendrimer-Containing Light-Emitting Diodes: Toward Site-Isolation of Chromophores , 2000 .

[27]  Shui-Tong Lee,et al.  Photoluminescence and electroluminescence of pyrazoline monomers and dimers , 2000 .

[28]  G. Bazan,et al.  Synthesis, Morphology, and Optical Properties of Tetrahedral Oligo(phenylenevinylene) Materials , 2000 .

[29]  A. Heeger,et al.  A Novel Series of Efficient Thiophene-Based Light-Emitting Conjugated Polymers and Application in Polymer Light-Emitting Diodes , 2000 .

[30]  Yu-Tai Tao,et al.  Novel Green Light‐Emitting Carbazole Derivatives: Potential Electroluminescent Materials , 2000 .

[31]  Synthesis of Octasubstituted Cyclooctatetraenes and Their Use as Electron Transporters in Organic Light Emitting Diodes , 2000 .

[32]  Y. Tao,et al.  Dipyrazolopyridine derivatives as bright blue electroluminescent materials , 2000 .

[33]  Y. Tao,et al.  Blue Light-Emitting Diodes Based on Dipyrazolopyridine Derivatives , 2000 .

[34]  Stephen R. Forrest,et al.  Efficient electrophosphorescence using a doped ambipolar conductive molecular organic thin film , 2001 .

[35]  G. Jung,et al.  An Efficient Pyridine- and Oxadiazole-Containing Hole-Blocking Material for Organic Light-Emitting Diodes: Synthesis, Crystal Structure, and Device Performance , 2001 .

[36]  E. Balasubramaniam,et al.  Organic Light-Emitting Diodes Based on Variously Substituted Pyrazoloquinolines as Emitting Material , 2001 .

[37]  I. Samuel,et al.  Polymeric Alkoxy PBD [2‐(4‐Biphenylyl)‐5‐Phenyl‐1,3,4‐Oxadiazole] for Light‐Emitting Diodes , 2001 .

[38]  Akio Yasuda,et al.  Improving the Performance of Polyfluorene-Based Organic Light-Emitting Diodes via End-Capping , 2001 .

[39]  M. Leclerc,et al.  Syntheses of Conjugated Polymers Derived from N-Alkyl-2,7-carbazoles , 2001 .

[40]  Y. Tao,et al.  Light-emitting carbazole derivatives: potential electroluminescent materials. , 2001, Journal of the American Chemical Society.

[41]  Jiann T. Lin,et al.  Amorphous 2,3-Substituted Thiophenes: Potential Electroluminescent Materials , 2002 .

[42]  M. Leclerc,et al.  Electrochemical, Conductive, and Magnetic Properties of 2,7-Carbazole-Based Conjugated Polymers , 2002 .

[43]  M. Leclerc,et al.  Blue-Light-Emitting Conjugated Polymers Derived From 2,7-Carbazoles , 2002 .

[44]  Jiann T. Lin,et al.  Green and Yellow Electroluminescent Dipolar Carbazole Derivatives: Features and Benefits of Electron-Withdrawing Segments , 2002 .

[45]  Jianmin Shi,et al.  An Efficient Pure Blue Organic Light-Emitting Device with Low Driving Voltages , 2002 .

[46]  M. Leclerc,et al.  2,7-Carbazole-based conjugated polymers for blue, green, and red light emission , 2002 .

[47]  Y. Tao,et al.  High‐Tg Carbazole Derivatives as Blue‐Emitting Hole‐Transporting Materials for Electroluminescent Devices , 2003 .

[48]  High‐Efficiency Polymer Light‐Emitting Diodes with Stable Saturated Red Emission: Use of Carbazole‐Based Copolymer Blends in a Poly(p‐phenylenevinylene) Derivative , 2003 .

[49]  V. Jankauskas,et al.  Synthesis of conjugated carbazole trimers and pentamers by Suzuki coupling , 2003 .

[50]  Chung‐Chih Wu,et al.  Hole-transport properties of a furan-containing oligoaryl , 2003 .

[51]  Ken-Tsung Wong,et al.  Unusual nondispersive ambipolar carrier transport and high electron mobility in amorphous ter(9,9-diarylfluorene)s. , 2003, Journal of the American Chemical Society.

[52]  Bernard Kippelen,et al.  2,7‐Bis(diarylamino)‐9,9‐dimethylfluorenes as Hole‐Transport Materials for Organic Light‐Emitting Diodes , 2003 .

[53]  J. Ding,et al.  Synthesis and properties of random and alternating fluorene/carbazole copolymers for use in blue light-emitting devices , 2004 .

[54]  Y. Chien,et al.  Spiroconjugation-enhanced intermolecular charge transport , 2004 .

[55]  Peter Strohriegl,et al.  Novel 2,7-Linked Carbazole Trimers as Model Compounds for Conjugated Carbazole Polymers , 2004 .

[56]  Influences of oligomer length on carrier-transport properties of oligofluorenes , 2004 .

[57]  Abhishek P. Kulkarni,et al.  Electron Transport Materials for Organic Light-Emitting Diodes , 2004 .

[58]  Cyanocarbazole Derivatives for High‐Performance Electroluminescent Devices , 2004 .

[59]  Ken‐Tsung Wong,et al.  Enhancement of bipolar carrier transport in oligofluorene films through alignment in the liquid-crystalline phase , 2005 .

[60]  C. Shu,et al.  Novel distyrylcarbazole derivatives as hole-transporting blue emitters for electroluminescent devices , 2005 .

[61]  Yu-Tai Tao,et al.  High Tg blue emitting materials for electroluminescent devices , 2005 .

[62]  M. Leclerc,et al.  Polycarbazoles: 25 Years of Progress , 2005 .

[63]  M. P. Yeh,et al.  Synthesis and characterization of new fluorescent two-photon absorption chromophores , 2006 .

[64]  S. Grigalevicius.  3,6(2,7),9-Substituted carbazoles as electroactive amorphous materials for optoelectronics , 2006 .

[65]  Ken‐Tsung Wong,et al.  Employing ambipolar oligofluorene as the charge-generation layer in time-of-flight mobility measurements of organic thin films , 2006 .