Abstract
Further development of organic light-emitting diodes (OLEDs) requires a reduction in driving voltage. Exciplex upconversion-type OLEDs (ExUC-OLEDs), which are actively utilized to form exciplexes at the donor/acceptor interface, are an optimal solution for reducing the driving voltage. However, a phenomenon that cannot be explained by simple exciton diffusion is observed in these devices. Herein, an exciton capture layer is inserted into the emitter (donor) layer of ExUC-OLEDs to elucidate the exciton diffusion mechanism. All ExUC-OLEDs emit light via triplet–triplet upconversion (TTU) and at more than half the applied voltage (1 V) of the energy gap of the emitter material. In addition, long-range exciton diffusion of up to 40 nm is confirmed by TTU and singlet fission contributions.
Original language | English |
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Article number | 2300239 |
Journal | Physica Status Solidi (A) Applications and Materials Science |
Volume | 220 |
Issue number | 24 |
DOIs | |
State | Published - 2023/12 |
Keywords
- exciplex upconversion
- organic light-emitting diodes
- triplet state
- ultralow voltage
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Electrical and Electronic Engineering
- Materials Chemistry