Prediction and Design of Efficient Exciplex Emitters for High‐Efficiency, Thermally Activated Delayed‐Fluorescence Organic Light‐Emitting Diodes

Abstract

High-efficiency, thermally activated delayed-fluorescence organic light-emitting diodes based on exciplex emitters are demonstrated. The best device, based on a TAPC:DPTPCz emitter, shows a high external quantum efficiency of 15.4%. Strategies for predicting and designing efficient exciplex emitters are also provided. This approach allow prediction and design of efficient exciplex emitters for achieving high-efficiency organic light-emitting diodes, for future use in displays and lighting applications.

Efficient exciplex emission from intramolecular charge transfer material

“…Both intra molecular charge transferred (ICT) materials and exciplexes formed between electron donors and acceptors are recognized with TADF character [12][13][14][15]. Up till now, a great deal of ICT materials and exciplexes were proved have high emitting efficiencies [11,[16][17][18][19][20]. Among which, the most impressive OLEDs based on blue and green ICT emitters performed high EQE of 19.5% and near 30% respectively [11,13,21].…”

Ultralow-voltage Auger-electron-stimulated organic light-emitting diodes

“…Indeed, a high external quantum efficiency (EQE) (∼15.4%) fluorescent OLED based on exciplex emission has been reported recently by mixing a hole transporting material with a bipolar host material to form CT excitons. 28 Recently, a simple heterojunction device with a stack of p-type HTL and an n-type ETL also has been shown to yield an efficient (EQE ∼ 12.02%) exciplex emission. 29 It is known that the energy of exciton is lower than the energy difference in the unbound electron and hole pair.…”

Organic narrowband near-infrared photodetectors based on intermolecular charge-transfer absorption

“…Their decay can be optimized for efficient emission as recently demonstrated for ‘exciplex'-type OLEDs with a respectable external electroluminescence quantum yield of 15% (ref. 3). …”