Graphene nanoribbon blends with P3HT for organic electronics

Area of Science:

• Materials Science
• Organic Electronics
• Nanotechnology

Background:

• Organic field-effect transistors (OFETs) performance is limited by charge transport issues in polymeric semiconductors.
• Structural defects, grain boundaries, and amorphous domains in polymer films hinder efficient charge carrier movement.
• Graphene nanoribbons (GNRs) offer potential for improved charge transport due to their unique electronic properties.

Purpose of the Study:

• To enhance charge carrier mobility in OFETs by blending regioregular poly(3-hexylthiophene) (P3HT) with newly designed N=18 armchair graphene nanoribbons (GNRs).
• To investigate the impact of GNRs on the electrical characteristics and performance of OFET devices.
• To explore the potential of P3HT:GNR blend films for organic phototransistor (OPT) applications.

Main Methods:

• Bottom-up solution synthesis of N=18 armchair GNRs.
• Preparation of soluble/dispersible P3HT and GNRs.
• Single-step co-deposition of P3HT:GNR blend films for OFET fabrication.
• Electrical characterization of OFETs under dark and illuminated conditions.

Main Results:

• OFETs fabricated with P3HT:GNR blends exhibited a three-fold increase in charge carrier mobilities compared to pure P3HT devices.
• GNRs and their aggregates facilitated charge transport by connecting semiconductor domains, improving percolation.
• The Ion/Ioff ratio remained unaffected by GNR addition at various concentrations.
• Blend films demonstrated a tunable photoresponse, indicating potential for OPT applications.

Conclusions:

• Blending P3HT with GNRs is an effective strategy to enhance charge carrier mobility in OFETs.
• GNRs act as conductive pathways, overcoming limitations imposed by film morphology.
• The developed P3HT:GNR blends show promise for next-generation organic optoelectronic devices.