Abstract In an organic electroluminescent (EL) device, the recombination of injected holes and electrons produces what appears to be ion‐pair or charge‐transfer (CT) exciton, this CT exciton decays produce one photon directly, relaxes a low‐lying local (LE). Thus full utilization both energy LE should pathway for obtaining high‐efficiency EL. Here, twisting donor‐acceptor (D‐A) triphenylamine‐imidazol molecule, TPA‐PPI, is reported: its synthesis, photophysics, EL performance. Prepared by...

The development of near-infrared (NIR) organic light-emitting diodes (OLEDs) is growing interest. Donor-acceptor (D-A) chromophores have served as an important class NIR materials for OLED applications. However, the external quantum efficiencies (EQEs) OLEDs based on conventional D-A are typically below 1 %. Reported herein a butterfly-shaped compound, PTZ-BZP. A PTZ-BZP film displayed strong fluorescence with emission peak at 700 nm, and corresponding efficiency reached 16 Remarkably, EQE...

In principle, the ratio (Φ) of maximum quantum efficiencies for electroluminescence (EL) to photoluminescence (PL) can be expected approach unity, if exciton (bound electron–hole pair) generated from recombination injected electrons and holes in OLEDs has a sufficiently weak binding energy. However, seldom are examples Φ > 25% reported because strongly bound excitons most organic semiconductors nature. Here, twisting donor–acceptor triphenylamine‐thiadiazol molecule (TPA‐NZP) exhibits...

Excited state characters and components play a decisive role in photoluminescence (PL) electroluminescence (EL) properties of organic light‐emitting materials (OLEDS). Charge‐transfer (CT) is beneficial to enhance the singlet exciton utilizations fluorescent OLEDs by an activated reverse intersystem crossing process, due minimized triplet energy splitting CT excitons. However, dominant component emissive significantly reduces PL efficiency such materials. Here, strategy carry out fine...

For a donor–acceptor (D–A) molecule, there are three possible cases for its low‐lying excited state (S 1 ): π–π* (a localized electronic state), charge‐transfer (CT) delocalized and mixed or hybridized of CT (named here as the local charge transfer (HLCT) state). The HLCT is an important design next‐generation organic light‐emitting diode (OLED) materials with both high photoluminescence (PL) efficiency large fraction singlet exciton generation in electroluminescence (EL). According to...

Through adding two substituent phenyl groups on distyrylbenzene, we have obtained the cross stacking of 2,5-diphenyl-1,4-distyrylbenzene with trans double bonds (trans-DPDSB) in crystalline state. In such a cross-stacking mode, solid-state emission exhibits high-intensity, having characteristics similar to its single molecule. The organic light-emiiting diodes (OLEDs) attractive performance been achieved using trans-DPDSB as light-emitting layer, and amplified spontaneous needlelike crystals...

Pure organic persistent room-temperature phosphorescence (p-RTP) under ambient conditions is attractive but challenging due to the slow intersystem crossing process and susceptibility of triplet excitons. Fabrication pure RTP luminogens with simultaneously high efficiency ultralong lifetime still remains a daunting job, owing their conflicting requirements for T1 nature (n,π*) (π,π*) characteristics, respectively. Herein, group amide-based derivatives efficient p-RTP developed through...

A<italic>meta</italic>-linked donor–acceptor (D–A) structure was utilized to achieve high-efficiency and colour-purity near ultraviolet (NUV) in organic light-emitting diodes (OLEDs).

Tremendous efforts have been devoted to develop efficient deep blue organic light-emitting diodes (OLEDs) materials with CIEy < 0.10 (Commission International de L'Eclairage (CIE)) and match the National Television System Committee (NTSC) standard CIE (x, y) coordinates of (0.14, 0.08) for display applications. However, fluorescent an external quantum efficiency (EQE) over 5% are still rare. Herein, we report a phenanthroimidazole–sulfone hybrid donor–acceptor (D–A) molecule emission. D–A...

A very high singlet exciton ratio (∼93%) in the electroluminescence of triphenylamine-thiadiazole molecule TPA-NZP is attributed to reverse intersystem crossing (T→S) along high-lying charge-transfer state channel, denoted "hot exciton" mechanism. Compared with a "cold mechanism, this may be good strategy for designing next generation organic light-emitting materials utilization efficiency and radiation efficiency. As service our authors readers, journal provides supporting information...

Most organic piezochromic materials exhibit red-shifted and quenched emission as pressure increases. However, an abnormal phenomenon of pressure-induced blue-shifted enhanced is observed in a 9-(3-(1,2,2-triphenylvinyl)phenyl)anthracene crystal, which based on discrete π-π anthracene (AN) dimers stacking with tetraphenylethylene (TPE) spacer. A appears strengthens when the more than 1.23 GPa, it reaches maximum 4.28 GPa. This ascribed to cooperative effect between aggregation-induced TPE...

Abstract Organic light‐emitting diodes (OLEDs) can promise flexible, light weight, energy conservation, and many other advantages for next‐generation display lighting applications. However, achieving efficient blue electroluminescence still remains a challenge. Though both phosphorescent thermally activated delayed fluorescence materials realize high‐efficiency via effective triplet utilization, they need to be doped into appropriate host often suffer from certain degree of efficiency...

A greatly enhanced proportion of radiative excitons in non-doped blue electroluminescence with a maximum exciton utilizing efficiency (EUE) 85% is harvested the orthogonal cyano substituted, charge transfer (CT) emitter TPMCN, comparison to localized emission (LE)-like TPM low EUE 16%.

Fluorescence probes in the NIR-IIa region show drastically improved imaging owing to reduced photon scattering and autofluorescence biological tissues. Now, polymer dots (Pdots) are developed with a dual fluorescence enhancement mechanism. First, aggregation induced emission of phenothiazine was used reduce nonradiative decay pathways polymers condensed states. Second, quenching minimized by different levels steric hindrance further boost fluorescence. The resulting Pdots displayed QY ca....

Molecular switches have attracted increasing interest in the past decades, due to their broad applications data storage, optical gating, smart windows, and so on. However, up till now, most of molecular are operated solutions or polymer blends with stimuli light, heat, electric fields. Herein, we demonstrate first pressure-controllable switch a benzo[1,3]oxazine OX-1 crystal. Distinct from light-triggered tautomerization between two states, applying hydrostatic pressure on crystal results...

Abstract As a common feature in majority of malignant tumors, hypoxia has become the Achilles’ heel photodynamic therapy (PDT). The development type‐I photosensitizers that show hypoxia‐tolerant PDT efficiency provides straightforward way to address this issue. However, materials have rarely been discovered. Herein, π‐conjugated molecule with A–D–A configuration, COi6‐4Cl, is reported. H 2 O‐dispersible nanoparticle COi6‐4Cl can be activated by an 880 nm laser, and displays type I/II...

The development of efficient near‐infrared (NIR) emitting material is current focus. Donor–acceptor (D–A) architecture has been proved to be an effective strategy obtain narrow energy gap. Herein, a D–A‐type NIR fluorescent compound 2,3‐bis(4′‐(diphenylamino)‐[1,1′‐biphenyl]‐4‐yl)fumaronitrile (TPATCN) synthesized and fully characterized. As revealed by theoretical calculations photophysical experiments, TPATCN exerts the advantages relatively large dipole moment charge transfer state...

Herein, we report an anthracene-based material, 2-(anthracen-9-yl)thianthrene (), whose crystal exhibits excimer fluorescence with unexpected high luminous efficiency (up to 80%) and long lifetime (163.75 ns), due pairwise anthracene stacking. These results will update the traditional view that excimers are poorly efficient in photoluminescence.

Abstract Herein, a simple aza‐aromatic compound dibenzo[a,c]phenazine (DPPZ), which exhibits single‐molecule white light with ternary emission, consisting of simultaneous fluorescence (S 1 →S 0 ) and dual room‐temperature phosphorescence (RTP, T 2 is reported. The Commission Internationale de l' Éclairage coordinates DPPZ powder are (0.28, 0.33). To everyone's knowledge, this the first case to achieve emission RTP. This finding provides prototype strategy realize low‐cost, stable pure...

9,10-Bis(3′,5′-diphenylphenyl)anthracene [MAM], 9-(3′,5′-diphenylphenyl)-10-(3‴,5‴-diphenylbiphenyl-4″-yl)anthracene [MAT], and 9,10-bis(3″,5″-diphenylbiphenyl-4′-yl)anthracene [TAT] were newly synthesized through boration Suzuki aryl–aryl coupling reactions. We have demonstrated that the EL performance of blue-light emitters can be optimized improved by varying chemical structures side groups. In thin film state, three materials exhibit PLmax values in range 439–445 nm. MAM, MAT, TAT all...

Abstract The development of near‐infrared (NIR) organic light‐emitting diodes (OLEDs) is growing interest. Donor–acceptor (D–A) chromophores have served as an important class NIR materials for OLED applications. However, the external quantum efficiencies (EQEs) OLEDs based on conventional D–A are typically below 1 %. Reported herein a butterfly‐shaped compound, PTZ‐BZP. A PTZ‐BZP film displayed strong fluorescence with emission peak at 700 nm, and corresponding efficiency reached 16...

To obtain highly efficient and stable blue electroluminescence, two novel star-shaped compounds are purposefully designed synthesized, which composed of functional groups, central triphenylamine (TPA) peripheral anthracene (AN) or phenanthrene (PA) with obviously segregative electronic density distribution characteristics between the highest occupied molecular orbital lowest unoccupied (HOMO LUMO). As a light-emitting layer, they exhibit not only deep-blue but also good stability in organic...

Photoluminescence (PL) efficiency and exciton utilization are two key parameters to harvest high-efficiency electroluminescence (EL) in organic light-emitting diodes (OLEDs). But it is not easy simultaneously combine these characteristics (high PL high utilization) into a fluorescent material. In this work, an efficient combination was achieved through concepts of hybridized local charge-transfer (CT) state (HLCT) "hot exciton", which the former responsible for while latter contributes...

A highly efficient deep-blue OLED with a FHWM of 35 nm and CIE coordinate (0.161, 0.046) was obtained based on the fully twisting donor–acceptor molecule TPA–PIM.