Highly efficient single-stack hybrid cool white OLED utilizing blue thermally activated delayed fluorescent and...

Area of Science:

• Materials Science
• Organic Electronics
• Solid State Physics

Background:

• Organic light-emitting diodes (OLEDs) are crucial for display technologies.
• Achieving efficient and stable cool white emission in single-stack OLEDs remains a challenge.
• Hybrid approaches combining different emitter types offer potential for improved performance.

Purpose of the Study:

• To design and construct highly efficient single-stack hybrid cool white OLEDs.
• To optimize out-coupling efficiency for both blue and yellow emissions.
• To control exciton formation for desired cool white emission characteristics.

Main Methods:

• Utilized blue thermally activated delayed fluorescent (TADF) and yellow phosphorescent emitters.
• Engineered blue-yellow-blue multiple emitting layers (EMLs).
• Tuned ITO and total device thickness to satisfy antinode conditions for emissions.
• Manipulated recombination zone via host medium conductivity variation.

Main Results:

• Achieved a maximum external quantum efficiency of 23.1% for cool white emission.
• Obtained CIE color coordinates of (0.324, 0.337), indicating high-quality white light.
• Demonstrated effective control over exciton formation ratio and recombination zone.

Conclusions:

• The developed single-stack hybrid OLED architecture is highly viable for advanced display applications.
• Optimizing device thickness and charge conductivity is key to efficient hybrid white OLEDs.
• This approach offers a promising pathway for high-performance display technology.