Developing Efficient Dinuclear Pt(II) Complexes Based on the Triphenylamine Core for High-Efficiency...

Area of Science:

• Materials Science
• Organic Electronics
• Photochemistry

Background:

• Dinuclear platinum(II) complexes show promise for electroluminescence but often suffer from low efficiency.
• Triphenylamine-based ligands are explored to improve the properties of these complexes.

Purpose of the Study:

• To design and synthesize novel dinuclear platinum(II) complexes with improved electroluminescence performance.
• To investigate the relationship between molecular structure, photophysical properties, and device performance.

Main Methods:

• Synthesis of four dinuclear platinum(II) complexes based on a triphenylamine core.
• Characterization of photoluminescence quantum efficiencies (PLQEs) in doped films.
• Single-crystal X-ray diffraction for structural analysis of PyDPt.
• Fabrication and testing of solution-processed organic light-emitting diodes (OLEDs) using various electron transport materials.
• Analysis of angle-dependent photoluminescence (PL) spectra.

Main Results:

• The synthesized complexes exhibit emission colors ranging from yellow to red with high PLQEs up to 0.79.
• The solid-state structure of PyDPt was determined.
• OLEDs fabricated with 1,3,5-tri(m-pyridin-3-ylphenyl)benzene (TmPyPB) showed good charge balance due to its electron mobility and hole-blocking capabilities.
• Preferentially horizontal orientation of the complexes in doped films enhanced light outcoupling.
• The yellow OLED based on PyDPt achieved a record external quantum efficiency (EQE) of 22.4% and a peak current efficiency of 78.7 cd/A.

Conclusions:

• Dinuclear platinum(II) complexes based on a triphenylamine core can achieve high electroluminescence efficiencies.
• Strategic material design, including the use of appropriate electron transport layers and control over molecular orientation, is crucial for high-performance OLEDs.
• These findings highlight the significant potential of dinuclear platinum(II) complexes for advanced organic electronic applications.