Singlet generation yields in organic light-emitting diodes

Proceedings of the IEEE

Volumn 97, Issue 9, 2009, Pages 1597-1605

  Monkman, Andy P ^a   Rothe, Carsten ^a,b   King, Simon M ^a,c  

^a DURHAM UNIVERSITY   (United Kingdom)

^b NOVALED GmbH   (Germany)

^c Cambridge Display Technology Ltd   (United Kingdom)

Author keywords

Light emitting diode displays; Light emitting diodes; Organic compounds

Indexed keywords

DIODES; EXCITONS; LIGHT EMITTING DIODES; MOLECULES; ORGANIC COMPOUNDS; POLYMERS; QUANTUM THEORY;

CHARGE RECOMBINATIONS; DIRECT MEASUREMENT; INDIRECT MEASUREMENTS; LIGHT EMITTING DIODE DISPLAYS; MEASUREMENT TECHNIQUES; ORGANIC LIGHT-EMITTING DEVICES; POTENTIAL DIFFERENCE; QUANTUM MECHANICAL;

ORGANIC LIGHT EMITTING DIODES (OLED);

EID: 69449092475     PISSN: 00189219     EISSN: None     Source Type: Journal    
DOI: 10.1109/JPROC.2009.2021868     Document Type: Article

References (58)

1. K. Tandon, S. Ramasesha, and S. Mazumdar, "Electron correlation effects in electron-hole recombination in organic light-emitting diodes," Phys. Rev. B, vol.67, Jan. 15, 2003.
2. M. Wohlgenannt, K. Tandon, S. Mazumdar, S. Ramasesha, and Z. V. Vardeny, "Formation cross-sections of singlet and triplet excitons in 7r-conjugated polymers," Nature, vol.409, pp. 494-497, Jan. 25, 2001.
3. A. S. Dhoot, D. S. Ginger, D. Beljonne, Z. Shuai, and N. C. Greenham, "Triplet formation and decay in conjugated polymer devices," Chem. Phys. Lett., vol.360, pp. 195-201, Jul. 10, 2002.
4. L. C. Lin, H. F. Meng, J. T. Shy, S. F. Horng, L. S. Yu, C. H. Chen, H. H. Liaw, C. C. Huang, K. Y. Peng, and S. A. Chen, "Triplet-to-singlet exciton formation in poly(p-phenylene-vinylene) light-emitting diodes," Phys. Rev. Lett., vol.90, p. 036 601, Jan. 24, 2003.
5. J. S. Wilson, A. S. Dhoot, A. Seeley, M. S. Khan, A. Kohler, and R. H. Friend, "Spin-dependent exciton formation in pi-conjugated compounds," Nature, vol.413, pp. 828-831, Oct. 25, 2001.
6. Y. Cao, I. D. Parker, G. Yu, C. Zhang, and A. J. Heeger, "Improved quantum efficiency for electroluminescence in semiconducting polymers," Nature, vol.397, pp. 414-417, Feb. 4, 1999.
7. M. A. Baldo, D. F. O'Brien, M. E. Thompson, and S. R. Forrest, "Excitonic singlet-triplet ratio in a semiconducting organic thin film," Phys. Rev. B, vol.60, pp. 14422-14428, 1999.
8. J. S. Kim, P. K. H. Ho, N. C. Greenham, and R. H. Friend, "Electroluminescence emission pattern of organic light-emitting diodes: Implications for device efficiency calculations," J. Appl. Phys., vol.88, pp. 1073-1081, Jul. 15, 2000.
9. C. Rothe, S. King, H. A. Al Attar, and A. P. Monkman, "Direct measurement of the singlet generation yield in polymer light emitting diodes," Phys. Rev. Lett., vol.97, p. 076602, 2006.
10. S. King, C. Rothe, and A. Monkman, "Triplet build in and decay of isolated polyspirobifluorene chains in dilute solution," J. Chem. Phys., vol.121, pp. 10 803-10 808, Dec. 1, 2004.
11. A. P. Monkman, H. D. Burrows, L. J. Hartwell, L. E. Horsburgh, I. Hamblett, and S. Navaratnam, "Triplet energies of pi-conjugated polymers," Phys. Rev. Lett., vol.86, pp. 1358-1361, Feb. 12, 2001.
12. A. P. Monkman, H. D. Burrows, I. Hamblett, S. Navarathnam, M. Svensson, and M. R. Andersson, "The effect of conjugation length on triplet energies, electron derealization and electron-electron correlation in soluble polythiophenes," J. Chem. Phys., vol.115, pp. 9046-9049, Nov. 15, 2001.
13. J. S. de Melo, H. D. Burrows, M. Svensson, M. R. Andersson, and A. P. Monkman, "Photophysics of thiophene based polymers in solution: The role of nonradiative decay processes," J. Chem. Phys., vol.118, pp. 1550-1556, Jan. 15, 2003.
14. S. M. King, R. Matheson, F. B. Dias, and A. P. Monkman, "Enhanced triplet formation by twisted intramolecular charge-transfer excited states in conjugated oligomers and polymers," J. Phys. Chem. B, vol.112, pp. 8010-8016, Jul. 2008.
15. M. Segal, M. A. Baldo, R. J. Holmes, S. R. Forrest, and Z. G. Soos, "Excitonic singlet-triplet ratios in molecular and polymeric organic materials," Phys. Rev. B, vol.68, p. 075211, Aug. 2003.
16. M. Lee, M. Segal, Z. Soos, J. Shinar, and M. Baldo, "Yield of singlet excitons in organic light-emitting devices: A double modulation photoluminescence-detected magnetic resonance study," Phys. Rev. Lett., vol.94, p. 137403, 2005.
17. M. Segal, M. A. Baldo, M. K. Lee, J. Shinar, and Z. G. Soos, "Frequency response and origin of the spin-1/2 photoluminescence-detected magnetic resonance in a pi-conjugated polymer," Phys. Rev. B, vol.71, Jun. 2005.
18. M. Wohlgenannt, X. M. Jiang, Z. V. Vardeny, and R. A. J. Janssen, "Conjugation-length dependence of spin-dependent exciton formation rates in Pi-conjugated oligomers and polymers," Phys. Rev. Lett., vol.88, p. 4, May 2002.
19. M. K. Lee, M. Segal, Z. G. Soos, J. Shinar, and M. A. Baldo, "Yield of singlet excitons in organic light-emitting devices: A double modulation photoluminescence-detected magnetic resonance study," Phys. Rev. Lett., vol.94, Apr. 2005.
20. S. Sinha and A. P. Monkman, "Delayed recombination of detrapped space-charge carriers in poly 2-methoxy-5-(2′-ethyl-hexyloxy)-1, 4-phenylene vinylene-based light-emitting diode," J. Appl. Phys., vol.97, p. 114 505, Jun. 1, 2005.
21. S. Sinha, C. Rothe, R. Guntner, U. Scherf, and A. P. Monkman, "Electrophosphorescence and delayed electroluminescence from pristine polyfluorene thin-film devices at low temperature," Phys. Rev. Lett., vol.90, p. 127402, Mar. 28, 2003.
22. C. Rothe, S. King, and A. Monkman, "Long-range resonantly enhanced triplet formation in luminescent polymers doped with iridium complexes," Nature Mater., vol.5, pp. 463-466, Jun. 2006.
23. P. A. Lane, L. C. Palilis, D. F. O'Brien, C. Giebeler, A. J. Cadby, D. G. Lidzey, A. J. Campbell, W. Blau, and D. D. C. Bradley, "Origin of electrophosphorescence from a doped polymer light emitting diode," Phys. Rev. B, vol.6323, p. 235 206, Jun. 15, 2001.
24. H. A. Al Attar and A. R. Monkman, "Dopant effect on the charge injection, transport, and device efficiency of an electrophosphorescent polymeric light-emitting device," Adv. Functional Mater., vol.16, pp. 2231-2242, Nov. 3, 2006.
25. M. Tammer, R. W. T. Higgins, and A. P. Monkman, "High optical anisotropy in thin films of polyfluorene and its affect on the outcoupling of light in typical polymer light emitting diode structures," J. Appl. Phys., vol.91, pp. 4010-4013, Apr. 1, 2002.
26. E. J. W. List, R. Guentner, P. S. de Freitas, and U. Scherf, "The effect of keto defect sites on the emission properties of polyfluorene-type materials," Adv. Mater., vol.14, pp. 374-378, Mar. 4, 2002.
27. S. Hintschich, C. Rothe, S. Sinha, and A. P. Monkman, "Population and decay of keto states in conjugated polymers, " J. Chem. Phys., vol.119, p. 519 346, Mar. 26, 2003.
28. H. Becker, S. Heun, K. Treacher, A. Busing, and A. Falcou, Dig. Tech. Papers, 2002 vol. 33, p. 780.
29. A. van Dijken, A. Perro, E. A. Meulenkamp, and K. Brunner, "The influence of a PEDOT: PSS layer on the efficiency of a polymer light-emitting diode," Organic Electron., vol.4, pp. 131-141, Sep. 2003.
30. C. Rothe, H. A. Al Attar, and A. P. Monkman, "Absolute measurements of the triplet-triplet annihilation rate and the charge-carrier recombination layer thickness in working polymer light-emitting diodes based on polyspirobifluorene," Phys. Rev. B, vol.72, Oct. 2005.
31. D. Hertel, H. Bassler, R. Guentner, and U. Scherf, "Triplet-triplet annihilation in a poly(fluorene)-derivative," J. Chem. Phys., vol.115, pp. 10007-10013, Dec. 1, 2001.
32. C. Rothe and A. P. Monkman, "Triplet exciton migration in a conjugated polyfluorene," Phys. Rev. B, vol.68, p. 075208, Aug. 15, 2003.
33. C. Rothe, H. A. Al Attar, and A. P. Monkman, "Absolute measurements of the triplet-triplet annihilation rate and the charge-carrier recombination layer thickness in working polymer light-emitting diodes based on polyspirobifluorene," Phys. Rev. B, vol.72, p. 155 330, Oct. 2005.
34. C. Rothe and A. Monkman, "Dynamics and trap-depth distribution of triplet excited states in thin films of the light-emitting polymer poly (9,9-di(ethylhexyl)fluorene)," Phys. Rev. B, vol.65, p. 073201, Feb. 15, 2002.
35. P. W. M. Blom, M. J. M. dejong, and J. J. M. Vleggaar, "Electron and hole transport in poly(p-phenylene vinylene) devices," Appl. Phys. Lett., vol.68, pp. 3308-3310, Jun. 3, 1996.
36. C. Rothe, S. M. King, and A. P. Monkman, "Electric-field-induced singlet and triplet exciton quenching in films of the conjugated polymer polyspirobifluorene," Phys. Rev. B, vol.72, p. 085220, Aug. 2005.
37. H. D. Burrows, J. S. de Melo, C. Serpa, L. G. Arnaut, A. P. Monkman, I. Hamblett, and S. Navaratnam, "S-I similar to > T-1 intersystem crossing in pi-conjugated organic polymers," J. Chem. Phys., vol.115, pp. 9601-9606, Nov. 22, 2001.
38. S. M. King, C. Rothe, D. Dai, and A. P. Monkman, "Femtosecond ground state recovery: Measuring the intersystem crossing yield of polyspirobifluorene," J. Chem. Phys., vol.124, p. 234903, Jun. 21, 2006.
39. H. E. Lessing, A. von Jena, and M. Reichert, "Triplet yield determination and heavy-atom effect from ground-state repopulation kinetics," Chem. Phys. Lett., vol.42, p. 218, 1976.
40. S. King, C. Rothe, and A. P. Monkman, "Measurements of the absolute inter-system-crossing rates of polyspirobifluorene derivatives.
41. W. T. Simpson, "Resonance force theory of carotenoid pigments," J. Amer. Chem. Soc., vol.77, pp. 6164-6168, 1955.
42. W. T. Simpson, "Internal dispersion forces - The polyenes," J. Amer. Chem. Soc., vol.73, pp. 5363-5367, 1951.
43. S. Karabunarliev and E. R. Bittner, "Spin-dependent electron-hole capture kinetics in luminescent conjugated polymers," Phys. Rev. Lett., vol.90, Feb. 2003.
44. S. Karabunarliev and E. R. Bittner, "Dissipative dynamics of spin-dependent electron-hole capture in conjugated polymers," J. Chem. Phys., vol.119, pp. 3988-3995, Aug. 2003.
45. A. Monkman and D. Burrows, "Backbone planarity effects on triplet energies and electron-electron correlation in luminescent conjugated polymers," Synth. Metals, vol.141, pp. 81-86, Mar. 18, 2004.
46. S. W. Yin, L. P. Chen, P. F. Xuan, K. Q. Chen, and Z. Shuai, "Field effect on the singlet and triplet exciton formation in organic/polymeric light-emitting diodes, " J. Phys. Chem. B, vol.108, pp. 9608-9613, Jul. 2004.
47. W. Barford, "Theory of singlet exciton yield in light-emitting polymers," Phys. Rev. B, vol.70, Nov. 2004.
48. M. Das, S. Ramasesha, and S. Mazumdar, "Role of electron-electron interactions on spin effects in electron-hole recombination in organic light emitting diodes," Synth. Metals, vol.155, pp. 270-273, Nov. 2005.
49. S. Difley, D. Beljonne, and T. Van Voorhis, "On the singlet-triplet splitting of geminate electron-hole pairs in organic semiconductors," J. Amer. Chem. Soc., vol.130, pp. 3420-3427, Mar. 2008.
50. D. Beljonne, Z. G. Shuai, A. J. Ye, and J. L. Bredas, "Charge-recombination processes in oligomer- and polymer-based light-emitting diodes: A molecular picture," J. Soc. Inf. Display, vol.13, pp. 419-427, May 2005.
51. L. P. Chen, L. Y. Zhu, and Z. G. Shuai, "Singlet-triplet splittings and their relevance to the spin-dependent exciton formation in light-emitting polymers: An EOM/CCSD study," J. Phys. Chem. A, vol.110, pp. 13 349-13 354, Dec. 2006.
52. Y. Iwasaki, T. Osasa, M. Asahi, M. Matsumura, Y. Sakaguchi, and T. Suzuki, "Fractions of singlet and triplet excitons generated in organic light-emitting devices based on a polyphenylenevinylene derivative," Phys. Rev. B, vol.74, Nov. 2006.
53. C. Rothe, S. King, and A. P. Monkman, "Systematic study of the dynamics of triplet exciton transfer between conjugated host polymers and phosphorescent iridium (III) guest emitters," Phys. Rev. B, vol.73, p. 245 208, 2006.
54. C. Rothe, L. O. Palsson, and A. P. Monkman, "Singlet and triplet energy transfer in a benzil-doped, light emitting, solid-state conjugated polymer," Chem. Phys., vol.285, pp. 95-101, Dec. 1, 2002.
55. C. A. Parker and C. G. Hatchard, "Delayed fluorescence from solutions of anthracene and phenanthrene," Proc. Chem. Soc. London, p. 147, 1962.
56. C. A. Parker and C. G. Hatchard, "Delayed fluorescence from solutions of anthracene and phenanthrene," Proc. Roy. Soc. London A, Math. Phys. Sci., vol.269, p. 574, 1962.
57. C. Rothe, R. Guentner, U. Scherf, and A. P. Monkman, "Trap influenced properties of the delayed luminescence in thin solid films of the conjugated polymer poly(9,9-di(ethylhexyl)fluorene)," J. Chem. Phys., vol.115, pp. 9557-9562, Nov. 22, 2001.
58. C. Rothe, K. Brunner, I. Bach, S. Heun, and A. P. Monkman, "Effects of triplet exciton confinement induced by reduced conjugation length in polyspirobifluorene copolymers," J. Chem. Phys., vol.122, p. 084706, Feb. 22, 2005.