High-Performance Doping-Free Hybrid White OLEDs Based on Blue Aggregation-Induced Emission Luminogens

Abstract

Doping-free white organic light-emitting diodes (DF-WOLEDs) have aroused research interest because of their simple properties. However, to achieve doping-free hybrid WOLEDs (DFH-WOLEDs), avoiding aggregation-caused quenching is challenging. Herein, blue luminogens with aggregation-induced emission (AIE) characteristics, for the first time, have been demonstrated to develop DFH-WOLEDs. Unlike previous DFH-WOLEDs, both thin (<1 nm) and thick (>10 nm) AIE luminogen (AIEgen) can be used for devices, enhancing the flexibility. Two-color devices show (i) pure-white emission, (ii) high CRI (85), and (iii) high efficiency. Particularly, 19.0 lm W is the highest for pure-white DF-WOLEDs, while 35.0 lm W is the best for two-color hybrid WOLEDs with CRI ≥ 80. A three-color DFH-WOLED shows broad color-correlated temperature span (2301-11628 K), (i) the first sunlight-like OLED (2500-8000 K) operating at low voltages, (ii) the broadest span among sunlight-like OLED, and (iii) possesses comparable efficiency with the best doping counterpart. Another three-color DFH-WOLED exhibits CRI > 90 at ≥3000 cd m, (i) the first DF-WOLED with CRI ≥ 90 at high luminances, and (ii) the CRI (92.8) is not only the highest among AIE-based WOLEDs but also the highest among DF-WOLEDs. Such findings may unlock an alternative concept to develop DFH-WOLEDs.

Efficient Bipolar Blue AIEgens for High‐Performance Nondoped Blue OLEDs and Hybrid White OLEDs

“…This may be ascribed to the instability of the interlayer (TAPC) and the charge transport layers (TAPC and TmPyPB). [13c,20] Given the excellent thermal and morphological stabilities of TPE‐TAPBI, it is very promising to advance operation stability of blue OLEDs and WOLEDs by adopting more stable interlayers and charge transport materials for practical utilization.…”

“…The nondoped OLED device based on TPE‐TAPBI radiates strong blue light (CIE x , y = 0.15, 0.16) with an excellent external quantum efficiency of 5.73%, which outperforms the device of TriPE‐TAPBI. In addition, white OLEDs (WOLEDs) using TPE‐TAPBI neat film as the blue‐emitting component is fabricated, providing physiologically friendly warm white light with low color temperature, and total power, current and external quantum efficiencies of 70.5 lm W −1 , 76.0 cd A −1 , and 28%, respectively, at 1000 cd m −2 .…”

Emergence of Nanoplatelet Light-Emitting Diodes

“…In the case of efficiency, there is much room for EQE of NPL-LEDs to the theoretical limit of 20% (assuming the outcoupling factor is 0.2) [156]. According to Equation (1), the use of efficient NPLs, careful manipulation of charge distribution and the introduction of outcoupling technique are helpful to boost the EQE [157,158,159,160,161,162]. In addition, the introduction of tandem architecture is beneficial to the efficiency [163,164,165,166,167], although no tandem NPL-LED has been developed.…”

Pure exciplex-based white organic light-emitting diodes with imitation daylight emissions

“…[7][8][9][10][11][12][13] OLEDs which can effectively imitate daylight would be of particular use in high-latitude areas where sunlight exposure is highly seasonal. [14][15][16] In 2009, Jou et al proposed a sunlight-style OLED with a correlated color temperature (CCT) tunable from 2300 to 12 000 K, proving the possibility of fabricating a new low color temperature light source. 17 In 2013, the same group reported OLEDs with a candle light-style yellowish orange chromaticity with a power efficiency of 29 lm W À1 at 100 cd m À2 , a respective color rendering index (CRI) of 87 and a CCT of 2050 K. 18 The fabricated device minimized potential harmful effects of excessive blue emission on the human eye.…”