Raman and optical characterization of multilayer turbostratic graphene grown via chemical vapor deposition

TL;DR

This study characterizes multilayer turbostratic graphene grown by atmospheric-pressure CVD, revealing disordered stacking and distinct Raman features compared to low-pressure methods, with implications for material quality assessment.

Contribution

It provides detailed optical and Raman characterization of multilayer turbostratic graphene grown via atmospheric-pressure CVD, highlighting differences from low-pressure methods.

Findings

AP-CVD graphene contains significant multilayer regions.

Raman 2D peak shows systematic differences in energy, width, and intensity.

Multilayer graphene is rotationally disordered.

Abstract

We synthesize large-area graphene via atmospheric-pressure (AP) chemical vapor deposition (CVD) on copper, and transfer to SiO2 wafers. In contrast to low-pressure (LP) CVD on copper, optical contrast and atomic force microscopy measurements show AP-CVD graphene contains significant multi-layer areas. Raman spectroscopy always shows a single Lorentzian 2D peak, however systematic differences are observed in the 2D peak energy, width, and intensity for single- and multi-layer regions. We conclude that graphene multi-layers grown by AP-CVD on Cu are rotationally disordered.