Determination of the In-Plane Optical Conductivity of Multilayer Graphene Supported on a Transparent Substrate of Finite Thickness from Normal-Incidence Transmission Spectra
CHEN Ya-Qin**
Key Laboratory of Microelectronics Devices and Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029
Abstract：Normal-incidence transmission measurements are commonly used for determining the real part of the in-plane optical conductivities σ1(ω) of graphene layers. We present an accurate expression for σ1(ω) in a closed form for a multilayer graphene film supported on a finite-thickness transparent substrate. This form takes into account the coherent and incoherent multiple reflections of the system, whereas the traditional method assumes a semi-infinite substrate. The simulated results for graphene sheets with a layer number N≤10 show that no matter what the transparent substrate is, the accuracy to which σ1(ω) is determined by applying this expression is improved with no systematic error. Moreover, the layer number N can be exactly determined by simply dividing the σ1(ωp) value of N-layer graphene by the corresponding σ1(ωp) of monolayer graphene, where ωp is the peak frequency of the ordinary dielectric function's imaginary part ε2(ω) of graphene.
. [J]. 中国物理快报, 2014, 31(05): 57802-057802.
CHEN Ya-Qin. Determination of the In-Plane Optical Conductivity of Multilayer Graphene Supported on a Transparent Substrate of Finite Thickness from Normal-Incidence Transmission Spectra. Chin. Phys. Lett., 2014, 31(05): 57802-057802.
2014, Vol. 31 
