Effects of Substrates on Nucleation, Growth and Electrical Property of Vertical Few-Layer Graphene

A key common problem for vertical few-layer graphene (VFLG) applications in electronic devices is the solution to grow on substrates. In this study, four kinds of substrates (silicon, stainless-steel, quartz and carbon-cloth) were examined to understand the mechanism of the nucleation and growth of VFLG by using the inductively-coupled plasma-enhanced chemical vapor deposition (ICPCVD) method. The theoretical and experimental results show that the initial nucleation of VFLG was influenced by the properties of the substrates. Surface energy and catalysis of substrates had a significant effect on controlling nucleation density and nucleation rate of VFLG at the initial growth stage. The quality of the VFLG sheet rarely had a relationship with this kind of substrate and was prone to being influenced by growth conditions. The characterization of conductivity and field emissions for a single VFLG were examined in order to understand the influence of substrates on the electrical property. The results showed that there was little difference in the conductivity of the VFLG sheet grown on the four substrates, while the interfacial contact resistance of VFLG on the four substrates showed a tremendous difference due to the different properties of said substrates. Therefore, the field emission characterization of the VFLG sheet grown on stainless-steel substrate was the best, with the maximum emission current of 35 mu A at a 160 V/mu m electrostatic field. This finding highlights the controllable interface of between VFLG and substrates as an important issue for electrical application.

Automated summary

This study investigates the nucleation and growth mechanism of vertical few-layer graphene (VFLG) on different substrates and finds that the properties of substrates have a significant impact on the initial nucleation and growth of VFLG. The quality of VFLG is less related to the substrate and more influenced by growth conditions. Additionally, the study shows that the conductivity of VFLG is similar on different substrates, but the interfacial contact resistance varies greatly. Stainless-steel substrate is found to be the most favorable for electrical applications.