Influence of nitrogen on the growth of vertical graphene nanosheets under plasma

TL;DR

This study explores how nitrogen gas influences the growth, morphology, and electronic properties of vertical graphene nanosheets produced via plasma-enhanced chemical vapor deposition, revealing tunable surface and electrical characteristics.

Contribution

It demonstrates that nitrogen gas can enhance nucleation, growth rate, and doping of vertical graphene nanosheets, with optimal concentration improving their properties.

Findings

Vertical graphene nanosheet density increases with nitrogen up to a limit.

Nitrogen incorporation affects sheet resistance and mobility.

Surface morphology and electronic properties can be tuned by nitrogen concentration.

Abstract

We have investigated the effect of nitrogen (N2) as a carrier gas on the growth of vertical graphene nanosheets (VGN) by plasma enhanced chemical vapor deposition (PECVD). It is demonstrated that addition of nitrogen gas with a hydrocarbon precursor can enhance the nucleation and growth rate of graphitic base layer as well as vertical sheets. The gas also simultaneously acts as an etchant and a dopant element. The density of vertical sheets increases up to certain limit and start to decrease with further increase in N2 concentration. The synthesized VGN exhibit sheet resistance from 0.89 to 1.89 K{\Omega}/sq. and mobility from 8.05 to 20.14 cm2/V-s, depending on the morphology and type of carrier concentration. These results reveal that the surface morphology and electronic properties of VGN can be tuned by incorporation of nitrogen gas during the growth phase.