• 文献标题:   A Phase Transition Oxide/Graphene Interface for Incident-Angle-Agile, Ultrabroadband, and Deep THz Modulation
  • 文献类型:   Article
  • 作  者:   ZHU HF, LI J, DU LH, HUANG WX, LIU JB, ZHOU JH, CHEN YF, DAS S, SHI QW, ZHU LG, LIU CL
  • 作者关键词:   2d, 3d interface, impedance matching, phase transition oxide, terahertz modulation
  • 出版物名称:   ADVANCED MATERIALS INTERFACES
  • ISSN:   2196-7350
  • 通讯作者地址:   Sichuan Univ
  • 被引频次:   0
  • DOI:   10.1002/admi.202001297 EA NOV 2020
  • 出版年:   2020

▎ 摘  要

Although plenty of functional materials have been explored to dynamically control the terahertz (THz) transmission, the limits in modulation depth, operation bandwidth, or angle-agile characteristics hinder their applications in highly active THz devices. Here, a 2D/3D (graphene/phase transition oxide VO2) interface is demonstrated for unprecedented high-efficiency modulation of THz waves with incident-angle-agile and ultrabroadband. An impedance matching state can be met at the graphene/VO2 interface by adjusting the stacked graphene layers, which leads to a minimal terahertz reflection amplitude. Then the interfacial impedance can be changed continuously via the semiconductor-metal phase transition of VO2 and achieve a THz switching. Based on this mechanism, this heterostructure demonstrates giant THz average amplitude modulation of 93%, 94%, and 96% in 0.3-1.5 THz at the incident angle of 35 degrees, 48 degrees, and 53 degrees, respectively. Moreover, the corresponding insertion loss is only -7.4, -4.1, and -6.5, which is much lower than most of the present THz modulation. These coupling phenomena and functions arising from the integration of 2D material and 3D phase transition oxide film broaden the previous materials system for dynamic controlling of THz wave, and would promote advanced THz smart devices for practical applications.