Highly Efficient Deep Blue Aggregation-Induced Emission Organic Molecule: A Promising Multifunctional Electroluminescence Material for Blue/Green/Orange/Red/White OLEDs with Superior Efficiency and Low Roll-Off

Abstract

For the constant demand of organic light-emitting diodes (OLEDs) with high efficiency, long lifetime, and low cost for display and lighting applications, the development of high-performance organic electroluminescence materials is key. Aggregation-induced emission (AIE) luminogens (AIEgens) provide a promising choice for their excellent performance in nondoped devices. Here we report a multifunctional deep blue AIE material, which can be used not only as an excellent blue emitter but also as a good host of green/orange/red phosphors. A deep blue nondoped OLED with a CIE y of 0.08 and high external quantum efficiency (EQE) of 7.0% is achieved. Furthermore, a series of green/orange/red phosphorescent OLEDs with high efficiency and low roll-off are obtained. Impressively, hybrid white OLEDs (WOLEDs) based on the deep blue AIEgen exhibit simultaneously high CRI (>90), excellent efficiency (EQEmax> 25%, PEmax = 99.9 lm W–1 for two-color WOLEDs, PEmax = 60.7 lm W–1 for four-color WOLEDs), low roll-off (PE1000nit = 72.1 lm W–1 for two-color WOLEDs, PE1000nit = 43.5 lm W–1 for four-color WOLEDs), and superior stable color, indicative of the multifunction of AIEgens. Accordingly, this work opens a new direction for achieving high-performance OLEDs, particularly offering a smart but simple way to depress the efficiency roll-off and reduce the cost of OLEDs for practical applications.

Mechanistic Study on High Efficiency Deep Blue AIE‐Based Organic Light‐Emitting Diodes by Magneto‐Electroluminescence

“…It has been reported that the nonradiative transition of AIE molecules will be largely reduced through the limited rotation of molecules in solid states, and that is the reason why AIE materials can still hold highly efficient emission when they aggregate together . Nowadays, the efficiency of some AIE‐based OLEDs has surpassed the traditional fluorescence efficiency limitation of 5% . However, the mechanism behind this improvement is still unclear.…”

Design and performance study of high efficiency/low efficiency roll-off/high CRI hybrid WOLEDs based on aggregation-induced emission materials as fluorescent emitters

“…It has been shown that TPB-AC possesses a high PL quantum yield (F PL ) of 98.6% and a high horizontal dipole ratio (Y 8 ) of 79%, and blue OLEDs based on TPB-AC achieved an EQE as high as 7.0%. 31,32 Moreover, we chose a green AIDF material, namely (4-(10Hphenoxazin-10-yl)phenyl)(9-phenyl-9H-carbazol-3-yl)methanone (CP-BP-PXZ), as the green emitting layer. As shown, CP-BP-PXZ has a high F PL of 58% and the EQE of the fabricated non-doped OLEDs reached 18.2% with an extremely low efficiency roll-off of 1.2% at a luminance of 1000 cd m À2 .…”

Violet-Blue Aggregation-Induced Emission Emitters for Non-Doped OLEDs with CIEy Smaller than 0.046

“…However, their CIEy values are still larger than 0.08. [33][34][35][36] Above results suggest that there might be a strong intramolecular charge transfer (ICT) between the A and D groups, which induce the emission red-shifted. Thus, to further blue-shift the emission of TPB-based AIEgens, one of the feasible strategies is to decrease the ICT process by weakening the electron accepting or donating ability.…”