Above 30% external quantum efficiency in green delayed fluorescent organic light-emitting diodes

Area of Science:

• Materials Science
• Organic Electronics
• Photophysics

Background:

• Organic light-emitting diodes (OLEDs) are crucial for displays and lighting.
• Thermally activated delayed fluorescence (TADF) materials offer high efficiency but require optimized host materials.
• Developing efficient green emitters remains a challenge in OLED technology.

Purpose of the Study:

• To investigate a novel host material for highly efficient green TADF OLEDs.
• To understand the photophysical properties and exciton harvesting capabilities of the host-dopant system.
• To optimize device structure for maximum external quantum efficiency.

Main Methods:

• Synthesis of 3-(3-(carbazole-9-yl)phenyl) pyrido[3',2':4,5]furo[2,3-b]pyridine (3CzPFP) host material.
• Fabrication and characterization of green TADF OLED devices using 3CzPFP:4CzIPN.
• Photoluminescence and device performance measurements.

Main Results:

• The 3CzPFP host material demonstrated excellent photoluminescence matching with the 4CzIPN dopant.
• A photoluminescence quantum yield of 100% was achieved for the 3CzPFP:4CzIPN film.
• A maximum external quantum efficiency of 31.2% was obtained for the green TADF OLED.

Conclusions:

• The novel 3CzPFP host material enables highly efficient green TADF OLEDs.
• Efficient exciton harvesting and high photoluminescence quantum yield are key to device performance.
• The developed TADF OLEDs show promising potential for advanced display and lighting applications.