Journal article
Single-step multiphonon emission model of spin-dependent exciton formation in organic semiconductors
Physical review. B, Condensed matter and materials physics, Vol.71(16), 165111
04/01/2005
DOI: 10.1103/PhysRevB.71.165111
Abstract
The maximum efficiency in organic light-emitting diodes depends on the ratio,
r
=
k
S
∕
k
T
, where
k
S
(
k
T
)
is the singlet (triplet) exciton formation rate. Several recent experiments found that
r
increases with increasing oligomer length starting from a value
r
≈
1
in monomers and short oligomers. Here, we model exciton formation as a single recombination step accompanied by multiphonon emission. Our model is based on two assertions. (i) More phonons are emitted in triplet formation than in singlet formation. (ii) The Huang-Rhys parameter for this phonon emission is smaller in long oligomers than in short ones. We justify these assertions based on recent experimental and theoretical data.
Details
- Title: Subtitle
- Single-step multiphonon emission model of spin-dependent exciton formation in organic semiconductors
- Creators
- M Wohlgenannt - University of Iowa, Physics and AstronomyO Mermer - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Physical review. B, Condensed matter and materials physics, Vol.71(16), 165111
- DOI
- 10.1103/PhysRevB.71.165111
- ISSN
- 1098-0121
- eISSN
- 1550-235X
- Publisher
- American Physical Society
- Language
- English
- Date published
- 04/01/2005
- Academic Unit
- IIHR--Hydroscience and Engineering; Physics and Astronomy
- Record Identifier
- 9984439157202771
Metrics
6 Record Views