Abstract
Triplet-triplet annihilation (TTA) in phosphorescent emission layers of modern organic light-emitting diodes
compromises their performance and device lifetime. TTA can occur by a Förster-type interaction between two
triplets, leading to a loss of one of them. The TTA process gives rise to correlations in the positions of the
surviving triplets, which complicate its study. These correlations can in principle be accounted for exactly in
kinetic Monte Carlo (KMC) simulations, but such simulations are computationally expensive. Here, we present
master equation modeling of TTA that accounts for correlations in a computationally efficient way. Cases without
and with triplet diffusion, which partly washes out correlations, are considered. We calculate the influence of
TTA on transient photoluminescence experiments, where it leads to a deviation from exponential decay, and on
steady-state emission efficiency. A comparison with KMC simulations shows that our master equation modeling
is an accurate and computationally competitive alternative.
compromises their performance and device lifetime. TTA can occur by a Förster-type interaction between two
triplets, leading to a loss of one of them. The TTA process gives rise to correlations in the positions of the
surviving triplets, which complicate its study. These correlations can in principle be accounted for exactly in
kinetic Monte Carlo (KMC) simulations, but such simulations are computationally expensive. Here, we present
master equation modeling of TTA that accounts for correlations in a computationally efficient way. Cases without
and with triplet diffusion, which partly washes out correlations, are considered. We calculate the influence of
TTA on transient photoluminescence experiments, where it leads to a deviation from exponential decay, and on
steady-state emission efficiency. A comparison with KMC simulations shows that our master equation modeling
is an accurate and computationally competitive alternative.
| Original language | English |
|---|---|
| Article number | 085202 |
| Number of pages | 14 |
| Journal | Physical Review B - Condensed Matter and Materials Physics |
| Volume | 105 |
| Issue number | 8 |
| DOIs | |
| Publication status | Published - 15 Feb 2022 |
Funding
This publication is part of the project “Master Equation Modeling of Organic Light-Emitting Diodes” (MEMOLED), with Project No. 17120, of the research programme “High Tech Systems and Materials” of the Netherlands Organization for Scientific Research (NWO). The project is jointly financed by NWO and Simbeyond B.V. We thank Stefano Gottardi, Harm van Eersel, and Marc Barbry from Simbeyond B.V. for interesting and intensive discussions about this work.
| Funders | Funder number |
|---|---|
| Simbeyond B.V. | |
| Nederlandse Organisatie voor Wetenschappelijk Onderzoek |
Keywords
- Optoelectronics
- Disordered systems (theory)
- Organic light emitting diode
- master equation
- many-body calculations
- Approximate methods for many-body systems