堆叠多层石墨烯的太赫兹电导研究

单层石墨烯具有可调的太赫兹电导,有望应用于制作新型太赫兹器件,然而这种调谐的变化范围有限,通过多层石墨烯的堆叠可以拓展石墨烯太赫兹器件的性能上限。本文通过太赫兹时域光谱研究了石英衬底上不同层数堆叠的石墨烯的太赫兹透过特性,并使用Drude模型以及菲涅尔定律对实验结果进行了理论模拟。实验数据与理论结果的匹配表明:随机堆叠的多层石墨烯在太赫兹波段可以看作没有电子耦合的多个单层石墨烯,其太赫兹电导具有更宽的调谐范围,同时化学掺杂可以进一步提高材料的载流子浓度,从而获得更高的太赫兹电导。

Study on the terahertz conductivity of stacked multilayer graphene

Monolayer graphene has tunable terahertz conductivity,therefore it has an excellent application prospect in potential new terahertz （THz）devices.In order to further extend the modulation depth of graphene-based THz devices,the study of stacked multilayer graphene will be very useful.In this paper,THz time-domain spectroscopy has been employed to investigate the transmission characteristics of stacked multilayer graphene samples on quartz substrates.Theoretical analysis based on Drude model and Fresnel coefficients have been used to explain the experimental phenomena.The results show that randomly stacked multilayer graphene which can be treated as multiple electronically decoupled monolayer graphene in the THz region has more extended variation range of THz conductivity.What is more,the carrier concentration in the material can be further improved by chemical doping,resulting in higher THz conductivity.