Development of a Highly Efficient Hybrid White Organic-Light-Emitting Diode with a Single Emission Layer by Solution...

Area of Science:

• Materials Science
• Organic Electronics
• Photophysics

Background:

• Organic light-emitting diodes (OLEDs) are crucial for displays and lighting.
• Achieving efficient and stable blue emission remains a challenge.
• Thermally activated delayed fluorescence (TADF) offers a pathway to high efficiency.

Purpose of the Study:

• To develop a high-performance solution-processed blue OLED using TADF materials.
• To investigate the potential of TADF emitters in hybrid white OLEDs.
• To reduce the hole-injection barrier for improved device efficiency.

Main Methods:

• Fabrication of a blue OLED using a mixed host and a blue TADF dopant (DMAC-TRZ).
• Doping the blue emission layer with a red phosphor (Ir(dpm)PQ2) to create a hybrid white OLED.
• Characterization of device performance, including brightness, efficiency, and color coordinates.

Main Results:

• The fabricated blue OLED achieved a maximum brightness of 57586 cd/m², current efficiency of 35.3 cd/A, and external quantum efficiency of 14.1%.
• The device exhibited excellent efficiency roll-off characteristics.
• The TADF-phosphor hybrid WOLED demonstrated a maximum brightness of 43594 cd/m² and high color rendering capabilities.

Conclusions:

• The developed mixed host effectively lowers the hole-injection barrier, enhancing device performance.
• Solution-processed TADF blue OLEDs and hybrid WOLEDs show promising results, outperforming existing technologies.
• This work represents the first report on a solution-processed TADF-phosphor hybrid WOLED.