Enhanced field emission from reduced graphene oxide polymer composites

Area of Science:

• Materials Science
• Nanotechnology
• Condensed Matter Physics

Background:

• Electron field emission (FE) is crucial for vacuum electronic devices.
• Reduced graphene oxide (rGO) and poly(3-hexylthiophene) (P3HT) are promising materials for FE applications.
• Optimizing composite structures is key to improving FE performance.

Purpose of the Study:

• To investigate the electron field emission properties of rGO:P3HT composite films.
• To determine the optimal rGO:P3HT ratio for enhanced field emission.
• To compare the performance of composite cathodes with traditional rGO/semiconductor structures.

Main Methods:

• Fabrication of three types of FE cathodes: rGO on n(+)-Si, rGO:P3HT composites with varying ratios, and rGO on rGO:P3HT composites.
• Characterization of field emission performance, including turn-on field and field enhancement factor.
• Analysis of composite film morphology and rGO-substrate interactions.

Main Results:

• A critical rGO:P3HT ratio was identified, leading to significantly improved field emission.
• The optimized composite cathode outperformed the rGO/n(+)-Si cathode.
• The best performance was achieved with a double-layer structure: rGO on rGO:P3HT composite, exhibiting a low turn-on field (~0.9 V/μm) and high field enhancement factor (~1900).

Conclusions:

• The morphology of the rGO:P3HT composite film and the interaction between rGO sheets and the substrate play vital roles in field emission.
• Composite materials offer a pathway to high-performance field emitters.
• Further optimization of composite structures can lead to advanced electron emission devices.