Abstract:
With the fast growing research and applications of graphene in photonics, understanding its
properties and their correlation over broad spectral range is essential. The study presented herein is an analysis
of optical conductivity and absorbance of chemical vapour deposition (CVD) single layer graphene (SLG).
Optical transmittance measurements of the SLG module were performed over photon energy range from nearultraviolet
(NUV, 300 nm) to near-infrared (NIR, 2500 nm) spectral regions. For photon wavelengths between
380 and 750 nm, graphene yielded an average transmittance of 97.6% with a maximum transparence peak of
98.3% at 710 nm wavelength. These results compares favorably with the reported theoretical
T( ) of 97.7%.
Arguably, the numerical value of optical conductivity,
for SLG (expressed in terms of universal optical
conductivity,
o
), equates to the absorbance (in units of
). Within the visible region, / o
= 1.04, which
shows a close approximation of
to
o
. However, within the NIR and NUV, this approximation of
disappears, where its value decreases sharply with energy in the NUV region. This behavior of the optical
conductivity approximating to the universal optical conductivity may be explained in terms of the contributions
from inter-band and intra-band transitions.
