Kinetic Monte Carlo modeling of the efficiency roll-off in a multilayer white organic light-emitting device
- Department of Applied Physics, Technische Universiteit Eindhoven, P.O. Box 513, NL-5600 MB Eindhoven (Netherlands)
- Simbeyond B.V., P.O. Box 513, NL-5600 MB Eindhoven (Netherlands)
Triplet-triplet annihilation (TTA) and triplet-polaron quenching (TPQ) in organic light-emitting devices (OLEDs) lead to a roll-off of the internal quantum efficiency (IQE) with increasing current density J. We employ a kinetic Monte Carlo modeling study to analyze the measured IQE and color balance as a function of J in a multilayer hybrid white OLED that combines fluorescent blue with phosphorescent green and red emission. We investigate two models for TTA and TPQ involving the phosphorescent green and red emitters: short-range nearest-neighbor quenching and long-range Förster-type quenching. Short-range quenching predicts roll-off to occur at much higher J than measured. Taking long-range quenching with Förster radii for TTA and TPQ equal to twice the Förster radii for exciton transfer leads to a fair description of the measured IQE-J curve, with the major contribution to the roll-off coming from TPQ. The measured decrease of the ratio of phosphorescent to fluorescent component of the emitted light with increasing J is correctly predicted. A proper description of the J-dependence of the ratio of red and green phosphorescent emission needs further model refinements.
- OSTI ID:
- 22591512
- Journal Information:
- Applied Physics Letters, Vol. 108, Issue 13; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
Similar Records
Monte Carlo study of efficiency roll-off of phosphorescent organic light-emitting diodes: Evidence for dominant role of triplet-polaron quenching
An intermediate model for fitting triplet–triplet annihilation in phosphorescent organic light emitting diode materials