Energy Transfer within Mixed Phase Polyfluorene Based Phosphorescent Electroluminescent Devices
| Autor: | Beatriz Romero, B. Arredondo, Araceli Gutiérrez-Llorente |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Materials science
Dopant business.industry Doping Analytical chemistry chemistry.chemical_element Phosphor Electroluminescence Surfaces Coatings and Films Electronic Optical and Magnetic Materials Condensed Matter::Materials Science Polyfluorene chemistry.chemical_compound General Energy chemistry Optoelectronics Iridium Physical and Theoretical Chemistry Phosphorescence business Diode |
| Zdroj: | The Journal of Physical Chemistry C. 116:4259-4266 |
| ISSN: | 1932-7455 1932-7447 |
| Popis: | The fraction of β chains is expected to have a strong influence on the energy transfer processes in organic light-emitting diodes based on mixed phase polyfluorene doped with transition metal phosphors. Here, we report on the electroluminescence emission properties of devices based on poly(9,9-dioctylfluorene), containing different fractions of β phase, doped with varying ratios of an iridium triplet emitter. We measure the electroluminescence spectra at constant current density and the current density–voltage characteristics of the diodes. We also investigate the temperature dependence of electroluminescence emission within a temperature range between 77 and 270 K in this system. For a given dopant concentration and β phase content, the electroluminescent emission covers a broad range of the spectrum. Trap-assisted recombination in β phase sites, which act as electron trapping sites, would compete with direct charge recombination in dopant sites, which might act as a hole trap. Singlet energy transfer se... |
| Databáze: | OpenAIRE |
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