High-Performance Semiconducting Carbon Nanotube Transistors Using Naphthalene Diimide-Based Polymers with Biaxially...

Area of Science:

• Materials Science
• Nanotechnology
• Polymer Chemistry

Background:

• High-purity semiconducting single-walled carbon nanotubes (sc-SWNTs) are crucial for advanced electronics.
• Conjugated polymers (CPs) are used to sort sc-SWNTs by chirality, but side-chain structure's impact is underexplored.
• Modifying CP side chains can influence sc-SWNT sorting efficiency.

Purpose of the Study:

• Investigate the effect of biaxially extended conjugated side chains in naphthalene diimide-based CPs on sc-SWNT sorting.
• Evaluate the performance of sc-SWNTs sorted using modified CPs in field-effect transistors.
• Establish a link between CP side-chain structure and sc-SWNT purity and device characteristics.

Main Methods:

• Synthesized naphthalene diimide-based CPs with various conjugated side chains.
• Utilized polymer wrapping to sort sc-SWNTs.
• Employed grazing incidence X-ray diffraction (GIXD) to analyze CP-SWNT interactions.
• Fabricated and tested field-effect transistor (FET) devices using sorted sc-SWNTs.

Main Results:

• A CP with a branched conjugated side chain (P3) showed reduced aggregation and improved wrapping ability.
• P3 facilitated the formation of larger bundles of high-purity sc-SWNTs.
• GIXD confirmed π-π stacking interactions between sc-SWNTs and CPs.
• FETs with P3/sc-SWNTs achieved high hole mobility (4.72 cm² V⁻¹ s⁻¹) and excellent stability.

Conclusions:

• Biaxially extended side-chain modification of CPs is a promising strategy for enhancing sc-SWNT sorting efficiency.
• The P3 polymer significantly improves the purity and performance of sc-SWNTs.
• This approach can lead to the development of more efficient and stable electronic devices based on SWNTs.