Determination of the In-Plane Optical Conductivity of Multilayer Graphene Supported on a Transparent Substrate of Finite Thickness from Normal-Incidence Transmission Spectra

• 来源期刊: 中国物理快报（英文版）
• 年，卷（期）: 2014,（5）
• 页码范围: 174-178
• 页数: 5页
• 语种: 中文
• DOI: 10.1088/0256-307X/31/5/057802

摘要

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.