Abstract

We have investigated white-emitting organic light-emitting devices (WOLEDs) making use of both blue-phosphor-sensitized orange-red fluorescence and the residual blue phosphorescence. By carefully adjusting the concentrations the phosphor and the fluorophore in the emitting layer and choosing the carrier-transport layers in the device structure, WOLEDs containing a single phosphor-sensitized emitting layer (type-I devices) can give colors close to the equal-energy white (0.33, 0.33), CRI up to 75, and efficiencies up to (10%, 23 cd/A, 13.4 lm/W). Furthermore, by doping a green phosphor into the poorly emitting electron-transport layer (type-II devices) to recycle excitons formed there, the EL efficiencies can be further enhanced up to (12.1%, 35.3 cd/A, 23.9 lm/W). In both types of devices, the phosphor sensitization reduces population of triplet excitons in the emitting region and substantially mitigates the efficiency roll-off with the driving current or brightness that is often observed in all-phosphor OLEDs. At the brightness of 1000 cd/m<sup>2</sup>, both types of devices retain quantum and cadmium per ampere (cd/A) efficiencies similar to their peak values.

© 2007 IEEE

PDF Article

References

  • View by:
  • |
  • |

  1. U.S. Gov. Printing Office, U. S. Dep. of EnergyWashingtonDCNational Lighting Inventory and Energy Consumption Estimate (2001)1.
  2. U.S. Gov. Printing Office, U. S. Dep. of EnergyWashingtonDCIlluminating the Challenges: Solid State Lighting Program Planning Workshop Report (2003).
  3. J. Kido, M. Kimura, K. Nagai, Science (, 1994) pp. 1332-1334.
  4. R. H. Jordan, A. Dodabalapur, M. Strukelj, T. M. Miller, "White organic electroluminescence devices," Appl. Phys. Lett. 68, 1192-1194 (1996).
  5. R. S. Deshpande, V. Bulovic', S. R. Forrest, "White-light-emitting organic electroluminescent devices based on interlayer sequential energy transfer," Appl. Phys. Lett. 75, 888-890 (1999).
  6. F. Steuber, J. Staudigel, M. Stössel, J. Simmerer, A. Winnacker, H. Spreitzer, F. Weissörtel, J. Salbeck, "White light emission from organic LEDs utilizing spiro compounds with high-temperature stability," Adv. Mater. 12, 130-133 (2000).
  7. C. W. Ko, Y. T. Tao, "Bright white organic light-emitting diode," Appl. Phys. Lett. 79, 4234-4236 (2001).
  8. B. W. D'Andrade, M. E. Thompson, S. R. Forrest, "Controlling exciton diffusion in multilayer white phosphorescent organic light emitting devices," Adv. Mater. 14, 147-151 (2002).
  9. S. Tokito, T. Iijima, T. Tsuzuki, F. Sato, "High-efficiency white phosphorescent organic light-emitting devices with greenish-blue and red-emitting layers," Appl. Phys. Lett. 83, 2459-2461 (2003).
  10. B. W. D'Andrade, R. J. Holmes, S. R. Forrest, "Efficient organic electrophosphorescent white-light-emitting device with a triple doped emissive layer," Adv. Mater. 16, 624-628 (2004).
  11. C. Adachi, M. A. Baldo, M. E. Thompson, S. R. Forrest, "Nearly 100% internal phosphorescence efficiency in an organic light emitting device," J. Appl. Phys. 90, 5048-5051 (2001).
  12. M. A. Baldo, M. E. Thompson, S. R. Forrest, "High-efficiency fluorescent organic light-emitting devices using a phosphorescent sensitizer," Nature (London) 403, 750-753 (2000).
  13. B. W. D'Andrade, M. A. Baldo, C. Adachi, J. Brooks, M. E. Thompson, S. R. Forrest, "High-efficiency yellow double-doped organic light-emitting devices based on phosphor-sensitized fluorescence," Appl. Phys. Lett. 79, 1045-1047 (2001).
  14. G. Lei, L. Wang, Y. Qiu, "Blue phosphorescent dye as sensitizer and emitter for white organic light-emitting diodes," Appl. Phys. Lett. 85, 5403-5405 (2004).
  15. Y. Kawamura, K. Goushi, J. Brooks, J. J. Brown, H. Sasabe, C. Adachi, "100% phosphorescence quantum efficiencies of Ir(III) complexes in organic semiconductor films," Appl. Phys. Lett. 86, 071104 (2005).
  16. R. J. Holmes, S. R. Forrest, Y.-J. Tung, R. C. Kwong, J. J. Brown, S. Garon, M. E. Thompson, "Blue organic electrophosphorescence using exothermic host-guest energy transfer," Appl. Phys. Lett. 82, 2422-2424 (2003).
  17. 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, "Highly efficient organic blue electrophosphorescent devices based on 3,6-Bis(triphenylsilyl)carbazole as the host material," Adv. Mater. 18, 1216-1220 (2006).
  18. T.-C. Chao, Y.-T. Lin, C.-Y. Yang, T.-H. Hung, H.-C. Chou, C.-C. Wu, K.-T. Wong, "Highly efficient UV organic light-emitting devices based on bi(9,9-diarylfluorene)s," Adv. Mater. 17, 992-996 (2005).
  19. C.-C. Wu, Y.-T. Lin, K.-T. Wong, R.-T. Chen, Y.-Y. Chien, "Efficient organic blue-light-emitting devices with double confinement on terfluorenes with ambipolar carrier transport properties," Adv. Mater. 16, 61-65 (2004).
  20. V. Bulović, A. Shoustikov, M. A. Baldo, E. Bose, V. G. Kozlov, M. E. Thompson, S. R. Forrest, "Bright, saturated, red-to-yellow organic light emitting devices based on polarization-induced spectral shifts," Chem. Phys. Lett. 287, 453-460 (1998).
  21. C. F. Madigan, V. Bulović, "Solid state salvation in amorphous organic thin films," Phys. Rev. Lett. 91, 247403-1-247403-4 (2003).
  22. B. W. D'Andrade, S. R. Forrest, "White organic light-emitting devices for solid-state lighting," Adv. Mater. (2004) pp. 1585-1595.
  23. Y. Sun, N. C. Giebink, H. Kanno, B. Ma, M. E. Thompson, S. R. Forrest, "Management of singlet and triplet excitons for efficient white organic light-emitting devices," Nature (London) 440, 908-912 (2006).

2006 (2)

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, "Highly efficient organic blue electrophosphorescent devices based on 3,6-Bis(triphenylsilyl)carbazole as the host material," Adv. Mater. 18, 1216-1220 (2006).

Y. Sun, N. C. Giebink, H. Kanno, B. Ma, M. E. Thompson, S. R. Forrest, "Management of singlet and triplet excitons for efficient white organic light-emitting devices," Nature (London) 440, 908-912 (2006).

2005 (2)

T.-C. Chao, Y.-T. Lin, C.-Y. Yang, T.-H. Hung, H.-C. Chou, C.-C. Wu, K.-T. Wong, "Highly efficient UV organic light-emitting devices based on bi(9,9-diarylfluorene)s," Adv. Mater. 17, 992-996 (2005).

Y. Kawamura, K. Goushi, J. Brooks, J. J. Brown, H. Sasabe, C. Adachi, "100% phosphorescence quantum efficiencies of Ir(III) complexes in organic semiconductor films," Appl. Phys. Lett. 86, 071104 (2005).

2004 (3)

G. Lei, L. Wang, Y. Qiu, "Blue phosphorescent dye as sensitizer and emitter for white organic light-emitting diodes," Appl. Phys. Lett. 85, 5403-5405 (2004).

C.-C. Wu, Y.-T. Lin, K.-T. Wong, R.-T. Chen, Y.-Y. Chien, "Efficient organic blue-light-emitting devices with double confinement on terfluorenes with ambipolar carrier transport properties," Adv. Mater. 16, 61-65 (2004).

B. W. D'Andrade, R. J. Holmes, S. R. Forrest, "Efficient organic electrophosphorescent white-light-emitting device with a triple doped emissive layer," Adv. Mater. 16, 624-628 (2004).

2003 (3)

S. Tokito, T. Iijima, T. Tsuzuki, F. Sato, "High-efficiency white phosphorescent organic light-emitting devices with greenish-blue and red-emitting layers," Appl. Phys. Lett. 83, 2459-2461 (2003).

R. J. Holmes, S. R. Forrest, Y.-J. Tung, R. C. Kwong, J. J. Brown, S. Garon, M. E. Thompson, "Blue organic electrophosphorescence using exothermic host-guest energy transfer," Appl. Phys. Lett. 82, 2422-2424 (2003).

C. F. Madigan, V. Bulović, "Solid state salvation in amorphous organic thin films," Phys. Rev. Lett. 91, 247403-1-247403-4 (2003).

2002 (1)

B. W. D'Andrade, M. E. Thompson, S. R. Forrest, "Controlling exciton diffusion in multilayer white phosphorescent organic light emitting devices," Adv. Mater. 14, 147-151 (2002).

2001 (3)

C. Adachi, M. A. Baldo, M. E. Thompson, S. R. Forrest, "Nearly 100% internal phosphorescence efficiency in an organic light emitting device," J. Appl. Phys. 90, 5048-5051 (2001).

C. W. Ko, Y. T. Tao, "Bright white organic light-emitting diode," Appl. Phys. Lett. 79, 4234-4236 (2001).

B. W. D'Andrade, M. A. Baldo, C. Adachi, J. Brooks, M. E. Thompson, S. R. Forrest, "High-efficiency yellow double-doped organic light-emitting devices based on phosphor-sensitized fluorescence," Appl. Phys. Lett. 79, 1045-1047 (2001).

2000 (2)

F. Steuber, J. Staudigel, M. Stössel, J. Simmerer, A. Winnacker, H. Spreitzer, F. Weissörtel, J. Salbeck, "White light emission from organic LEDs utilizing spiro compounds with high-temperature stability," Adv. Mater. 12, 130-133 (2000).

M. A. Baldo, M. E. Thompson, S. R. Forrest, "High-efficiency fluorescent organic light-emitting devices using a phosphorescent sensitizer," Nature (London) 403, 750-753 (2000).

1999 (1)

R. S. Deshpande, V. Bulovic', S. R. Forrest, "White-light-emitting organic electroluminescent devices based on interlayer sequential energy transfer," Appl. Phys. Lett. 75, 888-890 (1999).

1998 (1)

V. Bulović, A. Shoustikov, M. A. Baldo, E. Bose, V. G. Kozlov, M. E. Thompson, S. R. Forrest, "Bright, saturated, red-to-yellow organic light emitting devices based on polarization-induced spectral shifts," Chem. Phys. Lett. 287, 453-460 (1998).

1996 (1)

R. H. Jordan, A. Dodabalapur, M. Strukelj, T. M. Miller, "White organic electroluminescence devices," Appl. Phys. Lett. 68, 1192-1194 (1996).

Adv. Mater. (2)

B. W. D'Andrade, R. J. Holmes, S. R. Forrest, "Efficient organic electrophosphorescent white-light-emitting device with a triple doped emissive layer," Adv. Mater. 16, 624-628 (2004).

C.-C. Wu, Y.-T. Lin, K.-T. Wong, R.-T. Chen, Y.-Y. Chien, "Efficient organic blue-light-emitting devices with double confinement on terfluorenes with ambipolar carrier transport properties," Adv. Mater. 16, 61-65 (2004).

Adv. Mater. (4)

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, "Highly efficient organic blue electrophosphorescent devices based on 3,6-Bis(triphenylsilyl)carbazole as the host material," Adv. Mater. 18, 1216-1220 (2006).

T.-C. Chao, Y.-T. Lin, C.-Y. Yang, T.-H. Hung, H.-C. Chou, C.-C. Wu, K.-T. Wong, "Highly efficient UV organic light-emitting devices based on bi(9,9-diarylfluorene)s," Adv. Mater. 17, 992-996 (2005).

F. Steuber, J. Staudigel, M. Stössel, J. Simmerer, A. Winnacker, H. Spreitzer, F. Weissörtel, J. Salbeck, "White light emission from organic LEDs utilizing spiro compounds with high-temperature stability," Adv. Mater. 12, 130-133 (2000).

B. W. D'Andrade, M. E. Thompson, S. R. Forrest, "Controlling exciton diffusion in multilayer white phosphorescent organic light emitting devices," Adv. Mater. 14, 147-151 (2002).

Appl. Phys. Lett. (3)

S. Tokito, T. Iijima, T. Tsuzuki, F. Sato, "High-efficiency white phosphorescent organic light-emitting devices with greenish-blue and red-emitting layers," Appl. Phys. Lett. 83, 2459-2461 (2003).

R. S. Deshpande, V. Bulovic', S. R. Forrest, "White-light-emitting organic electroluminescent devices based on interlayer sequential energy transfer," Appl. Phys. Lett. 75, 888-890 (1999).

B. W. D'Andrade, M. A. Baldo, C. Adachi, J. Brooks, M. E. Thompson, S. R. Forrest, "High-efficiency yellow double-doped organic light-emitting devices based on phosphor-sensitized fluorescence," Appl. Phys. Lett. 79, 1045-1047 (2001).

Appl. Phys. Lett. (2)

Y. Kawamura, K. Goushi, J. Brooks, J. J. Brown, H. Sasabe, C. Adachi, "100% phosphorescence quantum efficiencies of Ir(III) complexes in organic semiconductor films," Appl. Phys. Lett. 86, 071104 (2005).

C. W. Ko, Y. T. Tao, "Bright white organic light-emitting diode," Appl. Phys. Lett. 79, 4234-4236 (2001).

Appl. Phys. Lett. (3)

R. H. Jordan, A. Dodabalapur, M. Strukelj, T. M. Miller, "White organic electroluminescence devices," Appl. Phys. Lett. 68, 1192-1194 (1996).

R. J. Holmes, S. R. Forrest, Y.-J. Tung, R. C. Kwong, J. J. Brown, S. Garon, M. E. Thompson, "Blue organic electrophosphorescence using exothermic host-guest energy transfer," Appl. Phys. Lett. 82, 2422-2424 (2003).

G. Lei, L. Wang, Y. Qiu, "Blue phosphorescent dye as sensitizer and emitter for white organic light-emitting diodes," Appl. Phys. Lett. 85, 5403-5405 (2004).

Chem. Phys. Lett. (1)

V. Bulović, A. Shoustikov, M. A. Baldo, E. Bose, V. G. Kozlov, M. E. Thompson, S. R. Forrest, "Bright, saturated, red-to-yellow organic light emitting devices based on polarization-induced spectral shifts," Chem. Phys. Lett. 287, 453-460 (1998).

J. Appl. Phys. (1)

C. Adachi, M. A. Baldo, M. E. Thompson, S. R. Forrest, "Nearly 100% internal phosphorescence efficiency in an organic light emitting device," J. Appl. Phys. 90, 5048-5051 (2001).

Nature (London) (2)

M. A. Baldo, M. E. Thompson, S. R. Forrest, "High-efficiency fluorescent organic light-emitting devices using a phosphorescent sensitizer," Nature (London) 403, 750-753 (2000).

Y. Sun, N. C. Giebink, H. Kanno, B. Ma, M. E. Thompson, S. R. Forrest, "Management of singlet and triplet excitons for efficient white organic light-emitting devices," Nature (London) 440, 908-912 (2006).

Phys. Rev. Lett. (1)

C. F. Madigan, V. Bulović, "Solid state salvation in amorphous organic thin films," Phys. Rev. Lett. 91, 247403-1-247403-4 (2003).

Other (4)

B. W. D'Andrade, S. R. Forrest, "White organic light-emitting devices for solid-state lighting," Adv. Mater. (2004) pp. 1585-1595.

U.S. Gov. Printing Office, U. S. Dep. of EnergyWashingtonDCNational Lighting Inventory and Energy Consumption Estimate (2001)1.

U.S. Gov. Printing Office, U. S. Dep. of EnergyWashingtonDCIlluminating the Challenges: Solid State Lighting Program Planning Workshop Report (2003).

J. Kido, M. Kimura, K. Nagai, Science (, 1994) pp. 1332-1334.

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.