Highly Efficient Soluble Blue Delayed Fluorescent and Hyperfluorescent Organic Light-Emitting Diodes by Host...

Area of Science:

• Materials Science
• Organic Electronics
• Photophysics

Background:

• Developing high-efficiency, solution-processable organic light-emitting diodes (OLEDs) is crucial for low-cost manufacturing.
• Blue OLEDs, in particular, face challenges in achieving high efficiency and stability.

Purpose of the Study:

• To engineer a novel host material and device structure for solution-processed, high-efficiency blue fluorescent and thermally activated delayed fluorescent (TADF) OLEDs.
• To demonstrate record external quantum efficiencies (EQEs) in solution-processed blue OLEDs.

Main Methods:

• Synthesis and characterization of a high triplet energy host material, (oxybis(3-(tert-butyl)-6,1-phenylene))bis(diphenylphosphine oxide) (DPOBBPE), designed for solution processing.
• Fabrication and performance evaluation of fluorescent and TADF OLED devices utilizing the DPOBBPE host.

Main Results:

• The DPOBBPE host exhibited excellent solubility, high photoluminescence quantum yield, and good film properties, making it suitable for solution processing.
• Solution-processed fluorescent OLEDs achieved a record EQE of 18.8%.
• Solution-processed blue TADF OLEDs achieved a record EQE of 25.8% with improved blue color coordinates.

Conclusions:

• The developed DPOBBPE host material and device architecture enable highly efficient, solution-processed blue OLEDs.
• These findings represent a significant advancement in achieving high-performance, cost-effective blue OLEDs for display and lighting applications.