Magnetic field effect on delayed fluorescence from pyrene crystals

Yarmus, L.; Swenberg, Charles E.; Rosenthal, Jenny E.; Arnold, Stephen

doi:10.1016/0375-9601(73)90565-3

Cited by 7 publications

(5 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Experimentally, 2 ao = 113 ± 20, hence and the acute bisector of the resonance directions (this should be the x axis) is at 30 ± 3° from the a direction (which was not determined with high accuracy). The experimental anisotropy in other planes, such as the (b, c') plane [6], is also compatible with the same D*/E*. It appears therefore that the mobile species responsible for T-T annihilation and delayed fluorescence at 300 K in pyrene is the triplet monomer exciton.…”

Section: Classificationsupporting

confidence: 66%

“…(5) is therefore also correct). Moreover, with the assumption of a Lorentzian shape, the anisotropy at high field is found to be, as in reference [2b] where w = AElk -, à is the resonance width and yoff and yon are given by (6) and (5).…”

Section: Classificationmentioning

confidence: 63%

“…Taking this into account, the best fit to experiment is obtained with hence k2 = kk 1 = 2.2 ± 1 x 109 s -1. From a similar analysis of the anisotropy in (b, c') plane, Yarmus et al [6] found and k -0.4. But bc' plane is less favourable than the plane chosen here for accurate analysis [2], as shown by the large uncertainty in D *IE *.…”

Section: Classificationmentioning

confidence: 71%

“…A further step of the present work will be the study of crystals intentionally doped with known substitutional impurities. 6. Conclusion.…”

Section: Classificationmentioning

confidence: 95%

“…Other aromatic crystals have now been shown to emit magnetic field sensitive delayed fluorescence. Among them is crystalline pyrene [6].…”

Section: Classificationmentioning

confidence: 99%

See 4 more Smart Citations

Magnetic field modulation of triplet-induced delayed fluorescence and photoenhanced currents in crystalline pyrene

1975

View full text Add to dashboard Cite

The effects of magnetic fields (0-6 kG) on the delayed fluorescence and photoenhanced currents in crystalline pyrene at 300 K can be explained qualitatively using the theories already used for anthracene. It is found that the moving triplet exciton has the same zero-field fine structure as the monomer exciton. In delayed fluorescence, triplet pair formation is diffusion limited with no long range interaction (rate constant 2.7 x 10-10 cm3 s-1) and pair lifetime is of the order of one hopping time, or 10-10 s, with no evidence of pair stabilization. In the study of photocurrents, two magnetic field effects, of opposite sign, are found. If the current is space-charge limited, triplets alter the ratio of free charge to trapped charge ; and the magnetic field acts through modulation of the triplet-trapped charge interaction rate constant. The rate constant for pair formation (1.7 x 10 -9 cm3 s-1) is found to be much larger than diffusion limited for nearest neighbour interaction, and implies a distance for pair formation of several tens of Å. Yet reaction of the pair thus formed to generate a singlet occurs only in about 10 % of cases. If the current is injection limited, triplets enhance the injection ability of the electrode, and the magnetic field acts through modulation of the triplet lifetime (by interaction with trapped charges), hence of the triplet density near the surface and the triplet flux to the electrode

show abstract

Section: Classificationsupporting

confidence: 66%

Section: Classificationmentioning

confidence: 63%