White-electrophosphorescence devices based on rhenium complexes

Efficient white emission from the mixing of yellow emission from the Re-complexes, (4,4′-dimethyl-2,2′-bipyridine)Re(CO)3Cl (Dmbpy-Re), and blue emission from the N,N′-di-1-naphthyl-N, N′-diphenylbenzidine (NPB) is reported. NPB is used as the hole-transporting layer. 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline is used as the exciton-blocking as well as electron-transporting layer. Dmbpy-Re is doped into the host material (4,4′-N-N′-dicarbazole)biphenyl (CBP). The chromaticity of the white emission can be tuned by adjusting the thickness of Dmbpy-Re:CBP layer or the concentration of Dmbpy-Re in CBP. The maximum luminance, efficiency, and Commission Internationale De L’Eclairage coordinates at 9 V of the devices with 20-nm-thick and 30-nm-thick Dmbpy-Re:CBP layer at a fixed Dmbpy-Re doping concentration of 2 wt % in CBP are 1332 cd/m2, 2.9 cd/A, and (0.30,0.37), and 2410 cd/m2, 5.1 cd/A, and (0.36,0.43), respectively. The turn-on voltage of these devices is ∼4 V.

[1]  S. Forrest,et al.  Nearly 100% internal phosphorescence efficiency in an organic light emitting device , 2001 .

[2]  Stephen R. Forrest,et al.  A surface-emitting vacuum-deposited organic light emitting device , 1997 .

[3]  Daniel Moses,et al.  Red electrophosphorescence from polymer doped with iridium complex , 2002 .

[4]  Jinghua Zhao,et al.  An efficient and bright organic white-light-emitting device , 2002 .

[5]  Stephen R. Forrest,et al.  Improved energy transfer in electrophosphorescent devices , 1999 .

[6]  Stephen R. Forrest,et al.  White Light Emission Using Triplet Excimers in Electrophosphorescent Organic Light‐Emitting Devices , 2002 .

[7]  Shiyong Liu,et al.  White light emission from exciplex using tris-(8-hydroxyquinoline)aluminum as chromaticity-tuning layer , 2001 .

[8]  Stephen R. Forrest,et al.  High-efficiency red electrophosphorescence devices , 2001 .

[9]  Shiyong Liu,et al.  Organic white light electroluminescent devices , 2000 .

[10]  S. Forrest,et al.  Highly efficient phosphorescent emission from organic electroluminescent devices , 1998, Nature.

[11]  Jingsong Huang,et al.  White light emission induced by confinement in organic multiheterostructures , 1999 .

[12]  G. Cheng,et al.  Electron injection and electroluminescence investigation of organic light-emitting devices based on a Sn/Al cathode , 2002 .

[13]  Joseph Shinar,et al.  Bright small molecular white organic light-emitting devices with two emission zones , 2002 .

[14]  Yu-Tai Tao,et al.  Bright white organic light-emitting diode , 2001 .

[15]  Mark E. Thompson,et al.  High-performance polymer light-emitting diodes doped with a red phosphorescent iridium complex , 2002 .

[16]  C. Tang,et al.  Enhanced electron injection in organic electroluminescence devices using an Al/LiF electrode , 1997 .

[17]  Y. Shirota,et al.  Exciplex formation at the organic solid-state interface: Yellow emission in organic light-emitting diodes using green-fluorescent tris(8-quinolinolato)aluminum and hole-transporting molecular materials with low ionization potentials , 1998 .

[18]  G. Gigli,et al.  White light emission from blends of blue-emitting organic molecules: A general route to the white organic light-emitting diode? , 2001 .

[19]  Stephen R. Forrest,et al.  A metal-free cathode for organic semiconductor devices , 1998 .

[20]  N. Peyghambarian,et al.  High-efficiency organic electrophophorescent devices through balance of charge injection , 2002 .

[21]  S. Chen,et al.  White light emission from exciplex in a bilayer device with two blue light-emitting polymers , 1998 .

[22]  Joseph Shinar,et al.  Bright white small molecular organic light-emitting devices based on a red-emitting guest–host layer and blue-emitting 4,4′-bis(2,2′-diphenylvinyl)-1,1′-biphenyl , 2002 .

[23]  Stephen R. Forrest,et al.  White-light-emitting organic electroluminescent devices based on interlayer sequential energy transfer , 1999 .

[24]  Giuseppe Gigli,et al.  Organic single-layer white light-emitting diodes by exciplex emission from spin-coated blends of blue-emitting molecules , 2003 .

[25]  Kahn,et al.  Chemistry and electronic properties of metal-organic semiconductor interfaces: Al, Ti, In, Sn, Ag, and Au on PTCDA. , 1996, Physical review. B, Condensed matter.

[26]  Yu Liu,et al.  Photoluminescent and electroluminescent properties of phenol-pyridine beryllium and carbonyl polypyridyl Re(I) complexes codeposited films , 2001 .

[27]  Jwo-Huei Jou,et al.  High-efficiency white organic light-emitting devices with dual doped structure , 2002 .

[28]  S. Forrest,et al.  VERY HIGH-EFFICIENCY GREEN ORGANIC LIGHT-EMITTING DEVICES BASED ON ELECTROPHOSPHORESCENCE , 1999 .

[29]  Shigeki Naka,et al.  Nondoped-type white organic electroluminescent devices utilizing complementary color and exciton diffusion , 2002 .

[30]  Stephen R. Forrest,et al.  Controlling Exciton Diffusion in Multilayer White Phosphorescent Organic Light Emitting Devices , 2002 .

[31]  Katsutoshi Nagai,et al.  Single‐layer white light‐emitting organic electroluminescent devices based on dye‐dispersed poly(N‐vinylcarbazole) , 1995 .

[32]  Lewis J. Rothberg,et al.  Color variation with electroluminescent organic semiconductors in multimode resonant cavities , 1994 .

[33]  A. Lees,et al.  Organometallic complexes as luminescence probes in monitoring thermal and photochemical polymerizations , 1998 .

[34]  Yuguang Ma,et al.  Electroluminescence from triplet metal—ligand charge-transfer excited state of transition metal complexes , 1998 .