The effect of molecular aggregation of thermally activated delayed fluorescence sensitizers for hyperfluorescence in organic light-emitting diodes

Abstract

DMAC-DPS showing AIE behavior increased TTA and STA, whereas Ph-OBNA showing ACQ behavior showed relatively small TTA and STA values due to the generation of excimers.

Organoboron-based multiple-resonance emitters: synthesis, structure–property correlations, and prospects

“…The synthesis of Ph-OBNA involved Suzuki–Miyaura coupling followed by cyclisation and N -aryl coupling reactions. 276 Although Ph-OBNA showed TADF properties, its planar structure led to excimer formation at high concentrations and ACQ. Another fused DOBNA derivative, DOBDiKTa , has a carbonyl-based MR structure ( QAO , here called DiKTa ) composed of two merged MR fragments.…”

Emerging hyperfluorescent emitters for solid-state lighting

“…No doubt, this approach demonstrates a path for designing several new HF emitters using the TADF emitter couple and their fruitful applications in OLEDs. [42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60] However, a low EQE (13.4%) was observed for the first blue HF-OLED based on the T4:F3 emitter couple (Table 1). This might be attributed to the incomplete FRET from the TADF emitter to the fluorescent emitter, as the TADF emitter (T4) emits at longer wavelength than the fluorescent emitter (F3), decreasing the spectral overlap J F (eqn ( 4)).…”

“…Indeed, they have been referred to as the fourth generation OLED active layers. [42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60] HF is defined as the emission mechanism that combines two different emitters, such as TADF and fluorescent emitters (Fig. 1c).…”

“…Therefore, HF has been established as a promising approach to design OLEDs with high color purity and enhanced stability. [42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60] The study of HF emitters and their optoelectronic applications is progressing with momentum. In this mini-review, we systematically documented the molecular design principles of HF emitters, their fundamental photophysical requirements, and the advances in HF-OLEDs.…”

One-Step Transformations from ACQ Luminogens to DSEgens via the Boc Protection Process

“…The development of new dual-state emission luminogens (DSEgens) has attracted increasing attention because of their wide potential application in various areas, such as optical devices, − chem-sensing, bioimaging, − tumor detection, and drug delivery systems . Normally, most of traditional organic fluorescent materials face the aggregation-caused quenching (ACQ) effect due to their planar structures, which cause the π – π stacking interactions in the solid state . After that, since the concept of aggregation-induced emission (AIE) was first coined by Tang and his co-workers, a large number of AIEgens have been developed with unique highly twisted conformations. − Obviously, both of them could only emit in a single solution or solid state, which may be detrimental to explore them as multi-functional fluorescent materials. − Thus, DSEgens may be more competitive than ACQ and AIE molecules to meet the growing demands for developing new advanced optical and biomedical materials. ,, …”