DIPz-TPTRZ Exciplex Films: Dual-Role Emitters and Hosts for Stable OLEDs with High-Efficiency and Reduced Efficiency...

Area of Science:

• Materials Science
• Organic Electronics
• Photophysics

Background:

• Exciplexes are crucial for thermally activated delayed fluorescence (TADF) but limited by OLED stability.
• Developing stable exciplex-based OLEDs requires robust donor and acceptor materials.

Purpose of the Study:

• To enhance the stability of exciplex-based organic light-emitting diodes (OLEDs).
• To investigate novel donor-acceptor pairs for efficient and stable TADF emission.
• To explore the use of exciplexes as host materials for fluorescent OLEDs.

Main Methods:

• Synthesized stable donor molecules (DIPz derivatives, BDDPD) and acceptor molecules (triazine derivatives).
• Fabricated exciplex-based OLED devices using these novel materials.
• Characterized photoluminescence quantum yield (PLQY), reverse intersystem crossing (RISC) rates, external quantum efficiency (EQE), and device lifetime (LT50).

Main Results:

• Achieved high PLQY and RISC rates with the developed exciplexes.
• Exciplex-based OLEDs reached a maximum EQE of 17.19% with minimal efficiency roll-off.
• Demonstrated excellent device stability with LT50 > 1000 hours at 1000 cd m⁻².
• Exciplexes successfully functioned as host materials, enabling red fluorescent OLEDs with EQE > 15% and reduced roll-off.

Conclusions:

• Introduced stable donor molecules to significantly improve exciplex-based OLED stability and performance.
• The developed exciplexes offer a promising strategy for efficient and long-lasting OLEDs.
• This work provides a new pathway for designing high-performance exciplex and fluorescent OLEDs.