Multiple Resonance Quasi-fluorescence from BN-Doped Aromatic Compounds Modified with "Naphthalene" Units Approaches the BT.2020 Green Light Standard.

Developing fluorophores that conform to the Broadcast Service Television 2020 (BT.2020) standard presents a formidable challenge. Here, we propose an innovative approach that integrates two and three-boron/nitrogen (BN2)-embedded [4]helicene subunits with naphthalene, resulting in the synthesis of two novel narrowband bright green quasi-fluorescent emitters, NT-2B and NT-3B for ultra-high-definition displays.

Regional Functionalization Molecular Design Strategy: A Key to Enhancing the Efficiency of Multi-Resonance OLEDs.

Herein, we propose a regional functionalization molecular design strategy that enables independent control of distinct pivotal parameters through different molecule segments. Three novel multiple resonances thermally activated delayed fluorescence (MR-TADF) emitters A-BN, DA-BN, and A-DBN, have been successfully synthesized by integrating highly rigid and three-dimensional adamantane-containing spirofluorene units into the MR framework. These molecules form two distinctive functional parts: part 1 comprises a boron-nitrogen (BN)-MR framework with adjacent benzene and fluorene units forming a central luminescent core characterized by an exceptionally rigid planar geometry, allowing for narrow FWHM values; part 2 includes peripheral mesitylene, benzene, and adamantyl groups, creating a unique three-dimensional "umbrella-like" conformation to mitigate intermolecular interactions and suppress exciton annihilation.

Optimizing the energy level alignment for achieving record-breaking efficiency in hot exciton deep red OLEDs.

To effectively compete with the quenching process in long-wavelength regions like deep red (DR) and near-infrared (NIR), rapid radiative decay is urgently needed to address the challenges posed by the "energy gap law". Herein, we confirmed that it is crucial for hot exciton emitters to attain a narrow energy gap (Δ) between the lowest singlet excited (S) state and second triplet excited (T) state, while ensuring that T slightly exceeds S in the energy level. Two proofs-of-concept of hot exciton DR emitters, namely αT-IPD and βT-IPD, were successfully designed and synthesized by coupling electron-acceptors ,-diphenylnaphthalen-2-amine (αTPA) and ,-diphenylnaphthalen-1-amine (βTPA) with an electron-withdrawing unit 5-(4-(-butyl) phenyl)-5H-pyrazino[2,3-]indole-2,3-dicarbonitrile (IPD).