Design of High-Performance Organic Semiconductors by Intra- and Intermolecular Charge Transfer Interaction

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Electrochemistry

Background:

• Charge transfer (CT) interactions are increasingly understood, offering new possibilities for designing materials with tunable electronic properties.
• The application of CT interactions in organizing supramolecules and cross-linked objects remains underexplored.
• π-conjugated systems are crucial for developing materials with unique electronic and optical characteristics.

Purpose of the Study:

• To synthesize and characterize novel π-conjugated oligomer charge transfer (CT) complexes.
• To investigate the intra- and intermolecular CT mechanisms within these complexes.
• To evaluate the potential of these CT complexes in energy storage applications.

Main Methods:

• Synthesis of π-conjugated oligomers with varying molar ratios of tetracyanoquinodimethane (TCNQ) and 1,6-diaminopyrene (1,6Py).
• Characterization of the crystalline structure and electronic properties of the TCNQ@Sq-1,6Py complexes.
• Electrochemical testing to determine electrical conductivity and capacitance performance, including doping with polyaniline (PANI).

Main Results:

• The 200%TCNQ@Sq-1,6Py CT complex exhibited stable intra- and intermolecular CT interactions.
• Achieved high electrical conductivity of 8.7 × 10⁻² S cm⁻¹ at room temperature.
• Demonstrated a specific capacitance of 70.62 F g⁻¹, significantly enhanced to 968.7 F g⁻¹ upon PANI doping, with 70% capacitance retention after 1000 cycles.

Conclusions:

• The synthesized π-conjugated oligomer CT complexes possess stable CT mechanisms and excellent electrochemical properties.
• These materials show significant promise for enhancing the performance of existing CT-based energy storage devices, particularly capacitors.
• The study highlights a new pathway for designing advanced functional materials using CT interactions.