Fluorescent Tetraphenylethylene-Based Europium Metal-Organic Framework for White-Light-Emitting Diodes

Area of Science:

• Materials Science
• Inorganic Chemistry
• Luminescence

Background:

• Metal-organic frameworks (MOFs) offer tunable properties for advanced applications.
• Europium-based MOFs (Eu-MOFs) are explored for their unique luminescent characteristics.
• Aggregation-induced emission (AIE) ligands enhance luminescence in solid states.

Purpose of the Study:

• To synthesize and characterize a novel AIE-active Eu-MOF, SYNU-4.
• To investigate the luminescent properties and thermal stability of SYNU-4.
• To evaluate SYNU-4's performance in white-light-emitting diode (WLED) applications.

Main Methods:

• Synthesis of SYNU-4 using a tetraphenylethylene derivative ligand.
• X-ray crystallography for structural determination (orthorhombic system).
• Optical spectroscopy for luminescence analysis (quantum yield, temperature dependence).
• Integration into UV-LED chips with commercial phosphors for WLED fabrication.

Main Results:

• SYNU-4 exhibits aggregation-induced emission (AIE) and remarkable thermal stability.
• A subtle antenna effect was observed due to energy level proximity between the ligand and Eu³⁺.
• Fluorescence quantum yield of 10.46% and stable luminescence over a wide temperature range.
• SYNU-4-based WLED achieved desirable color coordinates (0.33, 0.34), CCT of 5620 K, and CRI of 86.9.

Conclusions:

• SYNU-4 is a promising AIE-active Eu-MOF with excellent thermal and luminescence stability.
• The observed antenna effect enhances luminescence efficiency.
• SYNU-4 demonstrates significant potential for developing high-performance solid-state lighting, particularly WLEDs.