Dielectric and absorption properties of as-grown Bilayer and Single layer graphene at the microwave frequencies

Abstract

The advent of two-dimensional (2-D) graphene, single atomic thick layer of graphite, has stimulated the research interest in other 2-D materials. Transition-metal dichalcogenides (TMDs) are among them. Recently, 2D materials have demonstrated a promising material from the perspective of both fundamentals as well as applications. They exhibit unique optoelectronic properties, which can be largely tuned by varying the thickness. More recently, thermal chemical vapor deposition (CVD) or HFCVD have been developed for the growth of these 2D materials. Microwave measurements have been performed in microstrip line based test fixture to obtain the real and imaginary parts of complex relative permittivity, then the loss tangent and absorption coefficients of bilayer and single layer graphene are extracted. Bilayer graphene exhibits lower absorption coefficient of 0.6 dB/cm at 26.5 GHz. We envision that reported results would help to understand the dielectric and absorption properties of as-grown graphene layer in microwave frequency range.