High‐Performance Green OLEDs Using Thermally Activated Delayed Fluorescence with a Power Efficiency of over 100 lm W⁻¹

Abstract

A green organic light-emitting device (OLED) with an extremely high power efficiency of over 100 lm W(-1) is realized through energy transfer from an exciplex. An optimized OLED showed a maximum external efficiency of 25.7%, and a power efficiency of 79.4 lm W(-1) at 1000 cd m(-2) , which is 1.6-times higher than that of state-of-the-art green thermally activated delayed fluorescence (TADF) OLEDs.

Highly efficient inverted organic light-emitting diodes based on thermally activated delayed fluorescence

“…The device with an optimized ZnO thickness of 25 nm exhibited the maximum performance, with a current efficiency of 28.1 cd A −1 , a power efficiency of 16.1 lm W −1 , and an EQE of 9.8%. This performance is among the best of those reported for OLEDs based on phosphorescent or fluorescent emitters [7,9,13]. Fig.…”

“…Many efforts have been made to prepare high-performance OLEDs with excellent stability in the past two decades, and some products based on OLEDs have been introduced to the market [5][6][7]. Nevertheless, their intrinsic low environmental stability requires rigorous encapsulation to enhance their lifetime, which directly increases the final cost of the devices and thus limits the competiveness of OLEDs.…”

Exploiting the Potential of OLED-Based Photo-Organic Sensors for Biotechnological Applications

“…Nevertheless, it is lower than that of inorganic LEDs with efficiencies higher than 200 lm/W. However, monochromatic OLEDs with wavelengths ranging from 500-750 nm may achieve efficiencies of >100 lm/W [34]. Improvements in the OLED efficiency are attributed to: stacked OLED architecture, where individual OLEDs are built on top of each other; improved materials such as phosphorescent emitters; and optimization of light out-coupling.…”

Recent progress of green thermally activated delayed fluorescent emitters

“…A high PLQY of above 90% and a relatively short excited-state lifetime of 5.1 μs for delayed emission were reported using the 4CzIPN emitter. After the demonstration of a high EQE close to 20% using the organic 4CzIPN TADF emitter for the first time, several works optimizing the device structure of the 4CzIPN TADF OLEDs followed and reported an improved EQE surpassing the EQE obtained by Adachi et al Several bipolar host materials with a triplet energy high enough for both the singlet and triplet harvesting of 4CzIPN were proven to be better than the carbazoletype host materials and provided EQEs higher than 20% [8][9][10][11][12][13][14][15][16][17]. In particular, 3-(3-(carbazole-9-yl)phenyl) pyrido [3 ,2 :4,5]furo [2,3-b]pyridine (3CzPFP) was the best host material of 4CzIPN and realized the best EQE of 31.2% in the 4CzIPN devices [6].…”