High Performance Polymer Nanowire Field-Effect Transistors with Distinct Molecular Orientations

Area of Science:

• Materials Science
• Organic Electronics
• Polymer Chemistry

Background:

• Conjugated polymers are crucial for organic electronics.
• Controlling polymer morphology is key to optimizing device performance.
• Diketopyrrolopyrrole (DPP) based polymers offer promising optoelectronic properties.

Purpose of the Study:

• To investigate the self-assembly and charge transport properties of two similar DPP conjugated polymers.
• To understand the impact of polymer structure on nanowire configuration and mobility.
• To achieve high and balanced charge carrier mobilities in organic field-effect transistors (OFETs).

Main Methods:

• Synthesis of two diketopyrrolopyrrole conjugated polymers.
• Fabrication of polymer nanowires.
• Characterization of nanowire morphology using microscopy.
• Electrical characterization of field-effect transistors to measure charge carrier mobility.

Main Results:

• The two polymers with similar structures exhibited distinct "edge-on" and "face-on" molecular packing configurations in their nanowires.
• High hole mobility of 5.47 cm(2) V(-1) s(-1) was achieved.
• High electron mobility of 5.33 cm(2) V(-1) s(-1) was achieved.
• Well-balanced ambipolar charge transport was demonstrated.

Conclusions:

• Molecular structure significantly influences the self-assembly and resulting nanowire orientation.
• Achieving distinct "edge-on" and "face-on" configurations is possible with subtle structural variations.
• These DPP-based polymer nanowires show potential for high-performance ambipolar organic electronics.