High-mobility semiconducting naphthodithiophene copolymers.

Area of Science:

• Materials Science
• Organic Electronics
• Polymer Chemistry

Background:

• Organic semiconductors are crucial for developing advanced electronic devices.
• Polythiophene derivatives are widely studied for their semiconducting properties.
• Improving charge carrier mobility in organic semiconductors is a key research objective.

Purpose of the Study:

• To design and synthesize novel semiconducting polymers incorporating naphtho[1,2-b:5,6-b']dithiophene (NDT).
• To investigate the relationship between polymer structure, thin-film morphology, and organic field-effect transistor (OFET) performance.
• To explore the impact of isomeric heteroarenes on the electronic and physical properties of polythiophene-based semiconductors.

Main Methods:

• Synthesis of novel semiconducting polymers with NDT units in the polythiophene backbone.
• Fabrication and characterization of organic field-effect transistors (OFETs).
• Analysis of thin-film structures using techniques to assess molecular ordering and pi-stacking.

Main Results:

• Achieved high charge carrier mobilities (>0.5 cm(2) V(-1) s(-1)), among the highest for semiconducting polymers.
• Observed highly ordered thin-film structures with crystalline close pi-stacking, correlating with high mobility.
• Demonstrated that isomeric choices in heteroarenes significantly alter polymer properties and OFET performance, contrasting with small-molecule trends.

Conclusions:

• The designed NDT-containing polythiophenes are promising materials for high-performance printable electronics.
• Highly ordered thin-film structures are critical for achieving high charge carrier mobilities in these polymers.
• The study provides new insights into designing organic semiconducting materials by controlling isomeric structures.