Symmetric Mixed Sulfur-Selenium Fused Ring Systems as Potential Materials for Organic Field-Effect Transistors

Area of Science:

• Organic Chemistry
• Materials Science
• Solid-State Physics

Background:

• Fused aromatic systems are crucial for organic electronics.
• Chalcogenophene derivatives offer tunable electronic properties.
• Selenium incorporation can modify π-conjugation and intermolecular interactions.

Purpose of the Study:

• To synthesize novel fused chalcogenopheno[1]benzochalcogenophene (CBC) building blocks.
• To investigate the photophysical, electrochemical, and structural properties of CBC-based dimers.
• To evaluate the performance of these materials in organic field-effect transistors (OFETs).

Main Methods:

• Fiesselmann reaction for CBC synthesis.
• McMurry and Stille coupling for dimer formation.
• Photophysical and electrochemical characterization (UV-Vis, fluorescence, cyclic voltammetry).
• Single-crystal X-ray diffraction analysis.
• OFET device fabrication and characterization.

Main Results:

• A reliable synthetic route to CBC building blocks was established.
• Symmetric ene-linked dimers with reduced HOMO-LUMO gaps were synthesized.
• Strong intermolecular Se-Se and Se-C interactions were observed.
• Field-effect transistor mobilities reached up to 4×10⁻³ cm²/Vs with high on/off ratios.

Conclusions:

• CBC building blocks are versatile precursors for novel π-conjugated materials.
• Selenium incorporation enhances electronic properties and influences solid-state packing.
• These materials demonstrate potential for applications in organic electronics, particularly OFETs.