Abstract
We have measured the ratio, r = sigma(S)/sigma(T) of the formation cross section, sigma of singlet and triplet excitons from polarons in pi-conjugated oligomer and polymer films, using a spectroscopic technique we developed recently. We discovered a universal relation between r and the conjugation length (CL): r(-1) depends linearly on CL-1, irrespective of the chain structure. Since r is directly related to the maximum possible electroluminescence quantum efficiency in organic light emitting diodes (OLED), our results indicate that polymers have an advantage over small molecules in OLED applications.
Keywords
ElectroluminescenceOLEDExcitonConjugated systemPhysicsPolaronOligomerPolymerMaterials scienceSpin (aerodynamics)Singlet stateSigmaCrystallographyCondensed matter physicsAtomic physicsQuantum mechanicsThermodynamicsNanotechnologyChemistryNuclear magnetic resonanceExcited state
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Publication Info
- Year
- 2002
- Type
- article
- Volume
- 88
- Issue
- 19
- Pages
- 197401-197401
- Citations
- 148
- Access
- Closed
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Cite This
M. Wohlgenannt,
XM Jiang,
Z. V. Vardeny
et al.
(2002).
Conjugation-Length Dependence of Spin-Dependent Exciton Formation Rates in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>Π</mml:mi></mml:math>-Conjugated Oligomers and Polymers.
Physical Review Letters
, 88
(19)
, 197401-197401.
https://doi.org/10.1103/physrevlett.88.197401
Identifiers
- DOI
- 10.1103/physrevlett.88.197401
- PMID
- 12005663
- arXiv
- cond-mat/0112488