Wide-Range Color-Tunable Narrowband Fluorescence Emitters Based on 1,2-BN-Embedded Polycyclic Aromatic Hydrocarbons.

Area of Science:

• Molecular Optoelectronics
• Organic Chemistry
• Materials Science

Background:

• Developing polycyclic aromatic hydrocarbons (PAHs) with tunable, narrowband emission is crucial for advanced optoelectronic devices.
• Existing methods face challenges in achieving both wide-range color tunability and intrinsically narrowband emission.

Purpose of the Study:

• To establish a generalizable design principle for PAHs that reconciles wide-range color tunability with narrowband emission.
• To create a versatile platform for organic light-emitting diodes (OLEDs) with enhanced color gamut and efficiency.

Main Methods:

• Combined the aromatic localization effect (ALE) with heteroatomic topology engineering.
• Developed a 1,2-BN-fluoranthene embedding strategy via carbazole-assisted borylation.
• Synthesized a modular family of bis-boron-nitrogen-embedded PAHs ([B-N]2PAHs).

Main Results:

• Achieved emissions spanning the visible-to-near-infrared range (429-703 nm) with narrow full widths at half maximum (FWHM) down to 14 nm.
• Demonstrated chromaticities meeting the BT.2020 display standard, with some derivatives reaching the ProPhoto RGB gamut.
• Attained near-unity photoluminescence quantum yields (up to 99%) and high horizontal transition dipole ratios (up to 98.0%).
• Developed fluorescent OLEDs surpassing 40% external quantum efficiency (EQEmax), with specific devices reaching 35.5% and 44.3%.

Conclusions:

• The 1,2-BN-fluoranthene embedding strategy provides a viable platform for wide-color-gamut OLEDs.
• The synthesized [B-N]2PAHs offer a simpler, more generalizable synthetic blueprint compared to existing multiple-resonance (MR) emitters.
• This approach is readily extendable to diverse PAH architectures, paving the way for next-generation optoelectronic devices.