Raman spectroscopic investigations of carbon nanowalls

TL;DR

This study uses Raman spectroscopy to analyze the structural properties of carbon nanowalls grown on silicon, revealing their similarity to turbostratic graphite and the presence of defects.

Contribution

It provides a detailed Raman spectroscopic analysis of carbon nanowalls, comparing their spectral features with other carbon nanostructures and elucidating their structural characteristics.

Findings

CNWs exhibit D, G, D', G', and D+D' bands in Raman spectra.

Analysis indicates CNWs are similar to turbostratic graphite with many defects.

Raman bands of CNWs are comparable to those of graphene and nanotubes.

Abstract

Carbon nanowall (CNW) is a two dimensional graphitic nanostructures with many potential applications like field emission, catalyst support for fuel cell and negative electrode for batteries. CNWs were grown here on Si substrates by plasma enhanced chemical vapor deposition using N2/CH4 plasma at 6500C temperature. Deposited CNWs were characterized by scanning electron microscopy and Raman spectroscopy. Results obtained by Raman spectroscopic techniques are extensively studied. It shows existence of D, G, D/, G/, and D+D/ bands. These bands are analyzed to obtain detail structural information about CNWs. Analysis of each Raman band is done using a Lorentzian fit and their significance have been explained from the perspectives of CNWs. Different bands appeared in Raman spectra of CNWs have further been compared with of the same bands of graphene, single-wall and multi-wall nanotubes. Similarities and differences of CNWs with these carbon nanostructures have been pointed out during analysis. Our detailed analysis of the experimental results shows that CNWs have close similarity to turbostratic graphite i.e. with substantial amount of defects present in the graphene sheets stacked over one another.