Dicarbocation-Doped Polycyclic Aromatic Hydrocarbons with Efficient Deep-Red Narrowband Electroluminescence

Area of Science:

• Materials Science
• Organic Electronics
• Photochemistry

Background:

• Narrowband heteroaromatic emitters are crucial for wide-color-gamut displays.
• Developing efficient red-deep-red emitters remains a challenge.

Purpose of the Study:

• To design and synthesize novel dicarbocation-doped polycyclic aromatic hydrocarbon (PAH) emitters.
• To achieve efficient deep-red narrowband emission for display applications.

Main Methods:

• Synthesized undecacyclic aromatic skeletons doped with two para-positioned carbocations (C+) and four nitrogen atoms.
• Investigated the photophysical properties and electroluminescence performance of the emitters.
• Fabricated solution-processed organic light-emitting diodes (OLEDs).

Main Results:

• Achieved deep-red emission at 678–684 nm with narrow full width at half maxima (42–44 nm).
• Demonstrated a multiresonance effect leading to a reduced energy gap (1.80–1.83 eV).
• OLEDs exhibited high external quantum efficiencies (up to 20.4%) and excellent color purity (CIE: 0.720, 0.280), exceeding BT.2020 standards.

Conclusions:

• Multicarbocation-doped PAHs represent a new class of efficient, long-wavelength narrowband emitters.
• This molecular design overcomes limitations in current red-deep-red emitter technology.
• The developed emitters offer a promising pathway for next-generation display technologies.