High-efficiency small-molecule-based organic light emitting devices with solution processes and oxadiazole-based...

Area of Science:

• Materials Science
• Organic Electronics
• Photonics

Background:

• Phosphorescent organic light-emitting diodes (PHOLEDs) offer high efficiency for lighting and displays.
• Achieving high-efficiency white PHOLEDs via solution processing remains a challenge.

Purpose of the Study:

• To develop high-efficiency small-molecule-based white PHOLEDs using single-active-layer solution-based processes.
• To investigate the role of cathode structure and electron transport layers in device performance.

Main Methods:

• Fabrication of single-active-layer white PHOLEDs using solution processing.
• Codoping emitting layers with blue and orange phosphorescent dyes.
• Utilizing oxadiazole-based electron transport layers (ETLs) with CsF/Al cathodes.

Main Results:

• Achieved current efficiency of 17.3 cdA⁻¹ and luminous efficiency of 8.86 lmW⁻¹ at 1 mA cm⁻².
• Demonstrated improved electron transport and injection by CsF/Al cathodes with oxadiazole ETLs.
• Showcased significant enhancement in brightness and efficiency through optimized ETL/EIL/cathode structures.

Conclusions:

• Solution-processed white PHOLEDs can achieve high performance.
• Optimized cathode/ETL interfaces are crucial for efficient electron injection and transport.
• This approach offers a promising pathway for cost-effective, high-performance white PHOLED fabrication.