CN-116560112-B - Electrically driven active VO2MXene super-surface terahertz modulator

CN116560112BCN 116560112 BCN116560112 BCN 116560112BCN-116560112-B

Abstract

The invention relates to a preparation method of an electrically driven active VO 2 /MXene super-surface terahertz modulator, which utilizes a vacuum filtration method to prepare an MXene film. And preparing the MXene super surface by using a laser direct writing method. And preparing the vanadium dioxide film by utilizing a magnetron sputtering technology. And completely soaking the vanadium dioxide film on the prepared quartz substrate in a buffer oxide etching solution (BOE), fishing the self-supporting vanadium dioxide film from water by utilizing the prepared MXene super-surface to enable the vanadium dioxide film to be suspended on the MXene super-surface, standing the VO 2 /MXene composite super-surface for 1 hour, and waiting for the bonding and airing of the two to obtain the VO 2 /MXene composite super-surface. The MXene super surface has the advantages of high flexibility and easy preparation. The VO 2 /MXene terahertz modulator has the advantages of capability of actively regulating and controlling terahertz waves, high modulation depth and low trigger power.

Inventors

MA HE
LI YUAN
ZHANG XINPING

Assignees

北京工业大学

Dates

Publication Date: 20260505
Application Date: 20221205

Claims (3)

1. The preparation method of the electrically driven active VO 2 /MXene super-surface terahertz modulator is characterized by comprising the following steps of: 1) Firstly, preparing an MXene solution, then carrying out vacuum suction filtration on the MXene solution for 1 hour by using a suction pump, and drying a sample on a heating plate for 2 hours under the environment of 80 o ℃ to obtain a self-supporting MXene film; 2) Transferring the prepared self-supporting MXene film onto a quartz frame, placing a sample under a Nikon microscope, and focusing 800 nm laser on the sample by using a 50-time objective lens to obtain the MXene super-surface; 3) The method comprises the steps of preparing a vanadium dioxide film by utilizing a magnetron sputtering technology, clamping a quartz substrate on a substrate table of a magnetron sputtering instrument, sputtering by utilizing a pure vanadium target, enabling the pressure of a cavity of the substrate to be stable at 0.6 Pa at room temperature, performing magnetron sputtering at a target temperature of 30 o ℃ under the condition that the sputtering power is 55 and W, transferring a sample into a tube furnace after the sputtering is finished, introducing 3.5 multiplied by 10 -2 mbar of oxygen, stabilizing the pressure in the furnace at 4.5 Pa, heating the tube furnace to a temperature of 450 o ℃ and preserving heat for 10 minutes to finish annealing; 4) Preparing a self-supporting vanadium dioxide film by utilizing a nano-pore penetration etching method, and completely soaking the prepared vanadium dioxide film on the quartz substrate in a buffer oxide etching solution BOE solution to obtain a clean self-supporting vanadium dioxide film; 5) The prepared MXene super-surface is used for salvaging a self-supporting vanadium dioxide film from water, so that the vanadium dioxide film is suspended on the MXene super-surface, then the VO 2 /MXene composite super-surface is kept stand for 1 hour to wait for the bonding and airing of the two, the VO 2 /MXene composite super-surface is obtained, the composite super-surface is attached to a ceramic plate with holes, two electrodes are led out from two ends of the composite super-surface by using conductive silver adhesive bonding gold wires, and the two gold wires are connected to the electrodes at two ends of the ceramic plate, so that the VO 2 /MXene super-surface terahertz modulator is prepared.
2. The method of fabricating an electrically driven active VO 2 /MXene super-surface terahertz modulator according to claim 1, wherein rectangular holes with super-surface cell size of 320 x 65 mm 2 are designed with period of 15 x 15 array of 380 mm.
3. The method for manufacturing the electrically driven active VO 2 /MXene super-surface terahertz modulator according to claim 1, wherein the bottom substrate of the manufactured terahertz modulator is a quartz frame, the middle is 2.5 mm thick, the size is 1 cm 2 of the MXene super-surface, and the upper layer is a self-supporting vanadium dioxide thin film with a thickness of 150 nm thick.

Description

Electrically driven active VO 2/MXene super-surface terahertz modulator Technical Field The invention belongs to the field of super-surface terahertz modulators. Background Terahertz wave band is an important electromagnetic wave band for connecting electrons and photonics, and the frequency is 0.1-10THz. The terahertz wave photon has low energy, bandwidth and strong penetrability, and the advantages lead the terahertz wave photon to play an important role in the fields of aerospace communication, biological imaging, safety detection and the like. Because of the lack of materials for actively modulating terahertz waves, it is a great challenge to construct active terahertz modulation devices with high performance and high integration. The supersurface is an array of electromagnetic response cells of sub-wavelength scale. The supersurface may be configured to respond to the wavelength, amplitude, phase, and polarization of terahertz waves by designing a periodic structure, arrangement, and distribution. Researchers have widely studied metal and semiconductor supersurfaces. Although super-surface devices based on metal and semiconductor materials have been able to handle terahertz waves well, the inherent rigidity of conventional materials has made them unable to construct flexible terahertz devices. The carbon nano tube film has good flexibility and can be used for constructing a terahertz device with high flexibility. Most of the carbon nanotube-based supersurfaces are constructed using films containing metallic carbon nanotubes. These metallic carbon nanotube films have lower conductivities than metals and their charge carrier concentrations cannot be tuned as effectively as semiconductors. It is not easy to construct an active terahertz subsurface with a metallic carbon nanotube-based thin film. MXene is an emerging two-dimensional nanomaterial that has ultra-high flexibility, is easy to prepare in large areas, and has higher electrical conductivity than typical low-dimensional nanomaterial films such as graphene and carbon nanotube films. The MXene conductivity is 2X 10 6 S/m, the conductivity is twice that of the graphene film, one order of magnitude higher than that of the parallel carbon nano tube film, and two orders of magnitude higher than that of the random carbon nano tube film. Thus, MXene films are new candidates for preparing flexible supersurfaces. However, due to the lack of a method for actively regulating and controlling the conductivity of the MXene thin film, an active terahertz super-surface modulator based on MXene has not been realized so far. The metal-to-insulator transition (MIT) of vanadium dioxide (VO 2) around room temperature (68 ℃) has proven to be an excellent active terahertz modulation material with the advantages of high modulation depth, broadband, fast modulation speed and low insertion loss. Therefore, by finding a way to combine an MXene film with a VO 2 film, we can build a flexible, active terahertz subsurface with good performance. The traditional metal and semiconductor materials are unsuitable for being applied to more scenes due to the fact that the traditional metal and semiconductor materials cannot be bent, most of the current flexible terahertz super-surfaces are based on graphene and carbon nanotube films, the conductivity of the graphene and the carbon nanotube films is low, and further regulation and control of terahertz waves are limited. The super-surface device which is high in flexibility, high in conductivity, easy to prepare in a large area and capable of actively regulating and controlling terahertz waves is sought to be solved. Disclosure of Invention The invention realizes the active terahertz super-surface modulator with high modulation depth, low excitation power and low response time by compounding the self-supporting vanadium dioxide film and the MXene film with high flexibility and high conductivity. The preparation flow of the VO 2/MXene film terahertz super-surface modulator is shown in FIG. 1: 1. And preparing the MXene film by using a vacuum suction filtration method. Firstly, preparing an MXene solution by using a mild etching method, then carrying out vacuum suction filtration on the MXene solution for 1 hour by using a suction filtration pump, and placing a sample on a heating plate to be dried for 2 hours at 80 ℃ to obtain the self-supporting MXene film with the diameter of 3.5cm and the thickness of 2.5 mu m. 2. And preparing the MXene super surface by using a laser direct writing method. Transferring the prepared self-supporting MXene film onto a quartz frame, placing a sample under a Nikon microscope, focusing 800nm laser onto the sample by using a 50-time objective lens, designing rectangular holes with the super surface unit size of 320 multiplied by 65 mu m 2, and obtaining a 15 multiplied by 15 array with the period of 380 mu m in the x and y directions to obtain the MXene super surface. 3. And preparing the vanadium dioxide fi