Abstract
An organic light-emitting diode (OLED) with the blue emitter CC2TA showing thermally activated delayed fluorescence (TADF) is presented exhibiting an external quantum efficiency (ηEQE) of 11% ± 1%, which clearly exceeds the classical limit for fluorescent OLEDs. The analysis of the emission layer by angular dependent photoluminescence (PL) measurements shows a very high degree of 92% horizontally oriented transition dipole moments. Excited states lifetime measurements of the prompt fluorescent component under PL excitation yield a radiative quantum efficiency of 55% of the emitting species. Thus, the radiative exciton fraction has to be significantly higher than 25% due to TADF. Performing a simulation based efficiency analysis for the OLED under investigation allows for a quantification of individual contributions to the efficiency increase originating from horizontal emitter orientation and TADF. Remarkably, the strong horizontal emitter orientation leads to a light-outcoupling efficiency of more than 30%.
| Original language | English |
|---|---|
| Pages (from-to) | 5232-5239 |
| Number of pages | 8 |
| Journal | Advanced Functional Materials |
| Volume | 24 |
| Issue number | 33 |
| DOIs | |
| Publication status | Published - Sep 3 2014 |
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All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Biomaterials
- Condensed Matter Physics
- Electrochemistry
Cite this
Efficiency enhancement of organic light-emitting diodes incorporating a highly oriented thermally activated delayed fluorescence emitter. / Mayr, Christian; Lee, Sae Youn; Schmidt, Tobias D.; Yasuda, Takuma; Adachi, Chihaya; Brütting, Wolfgang.
In: Advanced Functional Materials, Vol. 24, No. 33, 03.09.2014, p. 5232-5239.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Efficiency enhancement of organic light-emitting diodes incorporating a highly oriented thermally activated delayed fluorescence emitter
AU - Mayr, Christian
AU - Lee, Sae Youn
AU - Schmidt, Tobias D.
AU - Yasuda, Takuma
AU - Adachi, Chihaya
AU - Brütting, Wolfgang
PY - 2014/9/3
Y1 - 2014/9/3
N2 - An organic light-emitting diode (OLED) with the blue emitter CC2TA showing thermally activated delayed fluorescence (TADF) is presented exhibiting an external quantum efficiency (ηEQE) of 11% ± 1%, which clearly exceeds the classical limit for fluorescent OLEDs. The analysis of the emission layer by angular dependent photoluminescence (PL) measurements shows a very high degree of 92% horizontally oriented transition dipole moments. Excited states lifetime measurements of the prompt fluorescent component under PL excitation yield a radiative quantum efficiency of 55% of the emitting species. Thus, the radiative exciton fraction has to be significantly higher than 25% due to TADF. Performing a simulation based efficiency analysis for the OLED under investigation allows for a quantification of individual contributions to the efficiency increase originating from horizontal emitter orientation and TADF. Remarkably, the strong horizontal emitter orientation leads to a light-outcoupling efficiency of more than 30%.
AB - An organic light-emitting diode (OLED) with the blue emitter CC2TA showing thermally activated delayed fluorescence (TADF) is presented exhibiting an external quantum efficiency (ηEQE) of 11% ± 1%, which clearly exceeds the classical limit for fluorescent OLEDs. The analysis of the emission layer by angular dependent photoluminescence (PL) measurements shows a very high degree of 92% horizontally oriented transition dipole moments. Excited states lifetime measurements of the prompt fluorescent component under PL excitation yield a radiative quantum efficiency of 55% of the emitting species. Thus, the radiative exciton fraction has to be significantly higher than 25% due to TADF. Performing a simulation based efficiency analysis for the OLED under investigation allows for a quantification of individual contributions to the efficiency increase originating from horizontal emitter orientation and TADF. Remarkably, the strong horizontal emitter orientation leads to a light-outcoupling efficiency of more than 30%.
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UR - http://www.scopus.com/inward/citedby.url?scp=84906946260&partnerID=8YFLogxK
U2 - 10.1002/adfm.201400495
DO - 10.1002/adfm.201400495
M3 - Article
AN - SCOPUS:84906946260
VL - 24
SP - 5232
EP - 5239
JO - Advanced Functional Materials
JF - Advanced Functional Materials
SN - 1616-301X
IS - 33
ER -