Optical Properties of Pyrolytic Carbon Films Versus Graphite and Graphene.

Galyna I Dovbeshko,Tommi Kaplas,Yuri P Svirko,Vsevolod V Cherepanov,Denys V Pidgirnyi,Vadim M Levin,Volodymyr R Romanyuk,Eugene O Andreev,Polina P Kuzhir

doi:10.1186/s11671-015-0946-8

Abstract

We report a comparative study of optical properties of 5–20 nm thick pyrolytic carbon (PyC) films, graphite, and graphene. The complex dielectric permittivity of PyC is obtained by measuring polarization-sensitive reflectance and transmittance spectra of the PyC films deposited on silica substrate. The Lorentz-Drude model describes well the general features of the optical properties of PyC from 360 to 1100 nm. By comparing the obtained results with literature data for graphene and highly ordered pyrolytic graphite, we found that in the visible spectral range, the effective dielectric permittivity of the ultrathin PyC films are comparable with those of graphite and graphene.

Highlights

Carbon can exist in a number of allotropic forms including diamond, graphite, graphene, fullerenes, and carbon nanotubes (CNT) that have a great deal of variability
In this work, the optical properties of pyrolytic carbon films in the visible spectral range have been studied with reflectance/transmittance spectroscopy
We have shown that dielectric permittivity of the pyrolytic carbon (PyC) films deposited on silica substrate are quite similar to those obtained for graphite and graphene

Summary

Introduction

Carbon can exist in a number of allotropic forms including diamond, graphite, graphene, fullerenes, and carbon nanotubes (CNT) that have a great deal of variability. Among planar carbon materials with sp hybridization of electron orbitals, the researchers were mainly focused on highly ordered pyrolytic graphite (HOPG) and graphene. HOPG is a highly ordered synthetic bulk material, which is characterized by strong anisotropy of optical, electronic, and elastic properties [1,2,3]. Optical and electronic properties of graphene are determined by zero bandgap and linear dependence of the electron energy on momentum in the vicinity of K-point of Brillouin zone. This in particular results in the nearly featureless visible absorption spectrum of graphene, which absorbs 2.3 % of incident radiation in the wavelength region of 350– 800 nm [4, 5]

Methods

Results

Conclusion