Transistor properties of salen-type metal complexes

Area of Science:

• Materials Science
• Organic Electronics
• Coordination Chemistry

Background:

• Schiff base complexes are investigated for their electronic properties.
• Organic semiconductors are crucial for developing advanced electronic devices.
• Understanding charge transport mechanisms in metal complexes is key to device optimization.

Purpose of the Study:

• To explore the p-channel transistor properties of Schiff base complexes derived from salicylaldehyde and various diamines.
• To investigate the role of the highest occupied molecular orbital (HOMO) and singly occupied molecular orbital (SOMO) in charge transport.
• To compare the performance of copper (Cu) and nickel (Ni) complexes in transistor applications.

Main Methods:

• Synthesis of Schiff base complexes using salicylaldehyde and ethylene-, propylene-, and trans-1,2-cyclohexanediamines.
• Characterization of the synthesized complexes.
• Fabrication and testing of p-channel field-effect transistors utilizing these complexes.
• Analysis of charge transport mechanisms through molecular orbital considerations.

Main Results:

• Schiff base complexes derived from salicylaldehyde and diamines demonstrate p-channel transistor characteristics.
• Copper complexes, despite being open-shell, facilitate hole transport via the HOMO, with the SOMO not participating in conduction.
• Nickel complexes generally exhibit higher charge carrier mobilities than copper complexes, potentially due to increased molecular planarity.
• The presence of the SOMO in these complexes does not adversely affect their transistor properties.

Conclusions:

• Schiff base metal complexes are viable candidates for p-channel organic field-effect transistors.
• The electronic structure, particularly the involvement of HOMO and the non-involvement of SOMO in conduction, is critical for transistor performance.
• Molecular design, including planarity, influences charge carrier mobility in these semiconductor materials.