Electrically driven active VO2/MXene metasurface for the terahertz modulation

With the growing demand for broadband wireless communication, high-resolution radar, security inspection, and biological analysis, terahertz (THz) technology has made significant progress in recent years. The wide applications of THz technology benefited from the rapid development of various THz functional devices. Metasurface, an essential means of manipulating THz waves, has widely been applied in multiple THz functional devices. However, it is still a great challenge to construct flexible THz metasurface devices due to the lack of flexibility of traditional semiconductor and metal materials. In this work, a two-dimensional material, MXene, is used to prepare flexible metasurfaces with frequency filtering and polarization functions. By further combining with the phase-transition-material vanadium dioxide, the VO2/MXene metasurface exhibits good performance in amplitude modulation under electrical stimulation. The modulation depth of the device reaches 86% under a lower trigger power of 11.6 mW/mm2 and the response time is only ∼100 ms. Such a flexible active metasurface with superior performance and high integration will be useful in THz imaging systems, THz sensing systems, etc.