A gate-controlled asymmetric bowtie antenna graphene terahertz detector and its preparation method

Abstract

The present application discloses a gate-controlled asymmetric bowtie antenna graphene terahertz detector and a preparation method thereof, including a graphene layer, an asymmetric bowtie antenna, an insulating dielectric layer, a gate metal electrode layer and a substrate layer; the asymmetric bowtie antenna is electrically connected to the graphene layer, and includes a first bowtie antenna and a second bowtie antenna that respectively partially cover both ends of the graphene layer, and a plurality of hollow structures for amplifying the thermophotovoltaic effect are provided in the middle of the first bowtie antenna or the second bowtie antenna; an insulating dielectric layer is provided on the side of the graphene layer away from the asymmetric bowtie antenna; the gate metal electrode layer is provided on the side of the insulating dielectric layer away from the graphene layer; the substrate layer is provided on the side of the gate metal electrode layer away from the insulating dielectric layer. The graphene terahertz wave detector provided by the present application can achieve high-response detection and polarization detection at room temperature.

Description

Technical Field

[0001] The present application relates to the technical field of terahertz wave detection, and particularly relates to a gated asymmetric bowtie antenna graphene terahertz detector and a preparation method thereof. Background Art

[0002] Terahertz waves refer to electromagnetic waves with frequencies in the range of 0.1 T to 10 THz, which have characteristics such as low photon energy, high penetrability, high bandwidth, high resolution, and rich molecular fingerprint spectra, making terahertz technology have broad application prospects in communication, biological imaging, medical diagnosis, security detection, etc. The core functional devices of terahertz technology mainly include terahertz sources, terahertz wave modulators, and terahertz wave detectors. Existing terahertz wave detectors mainly include thermal detectors, photonic detectors, and electronic detectors. However, existing terahertz wave detectors are limited by their structural composition and cannot achieve high-response and polarization-dependent terahertz wave detection under normal temperature conditions.

[0003] How to design a terahertz wave detector that works at normal temperature, has both a high response magnitude, and can detect the polarization characteristics of terahertz waves has become a key technical problem that needs to be solved urgently in this field. Summary of the Invention

[0004] The present application provides a gated asymmetric bowtie antenna graphene terahertz detector and a preparation method thereof to solve the technical problem of how to design a terahertz wave detector that works at normal temperature, has both a high response magnitude, and can detect the polarization characteristics of terahertz waves, reduce the environmental requirements of the terahertz wave detector, improve the response magnitude of the terahertz wave detector at normal temperature, and achieve polarization detection of terahertz signals.

[0005] In a first aspect, the present application provides a gated asymmetric bowtie antenna graphene terahertz detector, including: a graphene layer, an asymmetric bowtie antenna, an insulating dielectric layer, a gate metal electrode layer, and a substrate layer;

[0006] The asymmetric bowtie antenna is electrically connected to the graphene layer, and includes a first bowtie antenna and a second bowtie antenna. A plurality of hollow structures for amplifying the thermophotovoltaic effect are provided in the middle of the first bowtie antenna or the second bowtie antenna. The first bowtie antenna partially covers one end of the graphene layer, and the second bowtie antenna partially covers the other end of the graphene layer;

[0007] The insulating dielectric layer is provided on a side of the graphene layer away from the asymmetric bowtie antenna;

[0008] The gate metal electrode layer is provided on a side of the insulating dielectric layer away from the graphene layer;

[0009] The substrate layer is disposed on a side of the gate metal electrode layer away from the insulating dielectric layer.

[0010] Preferably, the hollow structure is fan-shaped.

[0011] Preferably, the thickness dimension range of the asymmetric bowtie antenna is 0.001 μm - 2 μm.

[0012] Preferably, the asymmetric bowtie antenna is a single material of any one of Al, Ag, Au, Bi, Cr, Ti, Ni, and ionic gel; or, the asymmetric bowtie antenna is a composite material composed of at least two of Al, Ag, Au, Bi, Cr, Ti, Ni, and ionic gel.

[0013] Preferably, a ring-shaped patch is disposed in the bowtie slot of the asymmetric bowtie antenna.

[0014] Preferably, the asymmetric bowtie antenna further includes an asymmetric coplanar waveguide feeding structure connected to the bowtie slot.

[0015] Preferably, the graphene layer is a single-layer or multi-layer graphene layer.

[0016] Preferably, the insulating dielectric layer is a single material of any one of SiO2, Al2O3, HfO2, Si3N4, MgO, MnO2, h-BN, diamond, mica, and polymer material thin films; or, the insulating dielectric layer is a composite material composed of at least two of SiO2, Al2O3, HfO2, Si3N4, MgO, MnO2, h-BN, diamond, mica, and polymer material thin films.

[0017] In a second aspect, the present application further provides a preparation method of a gate-controlled asymmetric bowtie antenna graphene terahertz detector for preparing the gate-controlled asymmetric bowtie antenna graphene terahertz detector as described above, and the preparation method includes:

[0018] Performing sputtering, deposition, or evaporation treatment on one surface of the obtained substrate layer to form a gate metal electrode layer;

[0019] Performing oxidation and deposition treatment on the surface of the substrate prepared with the gate metal electrode layer to form an insulating dielectric layer;

[0020] Transferring a graphene layer on a side of the insulating dielectric layer away from the substrate to obtain a graphene layer;

[0021] Performing photolithography, sputtering, deposition, or evaporation treatment on two opposite ends of the graphene layer to form an asymmetric bowtie antenna, so as to obtain the gate-controlled asymmetric bowtie antenna graphene terahertz detector.

[0022] The present application provides a gate-controlled asymmetric bowtie antenna graphene terahertz detector and a preparation method. Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0023] For the graphene terahertz wave detector provided by the present application, the graphene layer, the asymmetric bowtie antenna, and the gate metal electrode layer are used as the effective detection parts, which can effectively improve the response magnitude of the graphene terahertz wave detector at room temperature and realize polarization detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a front view structural schematic diagram of a gate-controlled asymmetric bowtie antenna graphene terahertz detector provided by a preferred embodiment of the present invention;

[0025] Figure 2 is a top view structural schematic diagram of a gate-controlled asymmetric bowtie antenna graphene terahertz detector provided by a preferred embodiment of the present invention;

[0026] Figure 3 is a schematic diagram of the light response magnitude at different gate voltages when the gate-controlled asymmetric bowtie antenna graphene terahertz detector provided by a preferred embodiment of the present invention is irradiated with a 2.52 THz laser;

[0027] Figure 4 is a schematic diagram of the ratio of the light response to the maximum light response magnitude when the gate-controlled asymmetric bowtie antenna graphene terahertz detector provided by a preferred embodiment of the present invention is irradiated with a 2.52 THz laser at different polarization angles;

[0028] Figure 5 is a graphene Raman scattering spectrogram of a gate-controlled asymmetric bowtie antenna graphene terahertz detector provided by a preferred embodiment of the present invention;

[0029] Figure 6 is a schematic diagram of the steps of a preparation method of a gate-controlled asymmetric bowtie antenna graphene terahertz detector provided by a preferred embodiment of the present invention;

[0030] 1 - First bowtie antenna, 2 - Graphene layer, 3 - Second bowtie antenna, 4 - Insulating dielectric layer, 5 - Gate metal electrode layer, 6 - Substrate layer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] The embodiments of the present application will be specifically described below in conjunction with the accompanying drawings. The provided examples are only for illustrative purposes and should not be construed as a limitation of the present application. The accompanying drawings are for reference and illustration only and do not constitute a limitation on the scope of patent protection of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application. In the description of the present application, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first", "second", "third", etc. may explicitly or implicitly include one or more of such features. In the description of the present application, unless otherwise specified, the meaning of "a plurality" is two or more.

[0032] In the description of the present application, it should be noted that unless otherwise clearly defined and limited, the terms "mounted", "connected", "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. The terms "vertical", "horizontal", "left", "right", "up", "down" and similar expressions used herein are only for illustrative purposes and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation of the present application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0033] In the description of the present application, it should be noted that unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0034] The asymmetric bowtie antenna is a variant of the bowtie antenna. The shapes of its upper and lower arms resemble a bowtie, but the geometric structures or dimensions of the two arms are not exactly the same, thus forming asymmetry. The cross-sectional widths of the two arms of the asymmetric bowtie antenna gradually widen from the middle to both sides, and the two arms overlap at the middle of the substrate. Therefore, the asymmetric bowtie antenna is actually an electric dipole, composed of two equal but opposite charges, which are separated by a certain distance at the center of the antenna, forming an electric dipole with opposite polarities. The asymmetric bowtie antenna has a relatively wide bandwidth characteristic, the electric field is perpendicular to the antenna axis, and its intensity is the largest in two directions, making its radiation characteristics superior.

[0035] The graphene layer is a composite material structure composed of graphene and other materials, with unique physical properties such as electrical, thermal, and optical properties.

[0036] In view of this, in the embodiments of the present application, a gated asymmetric bowtie antenna graphene terahertz detector is provided. Please refer to Figure 1 , which includes a graphene layer 2, an asymmetric bowtie antenna, an insulating dielectric layer 4, a gate metal electrode layer 5, and a substrate layer 6; the asymmetric bowtie antenna is electrically connected to the graphene layer 2, and includes a first bowtie antenna 1 and a second bowtie antenna 3. A number of hollow structures for amplifying the thermophotovoltaic effect are provided in the middle of the first bowtie antenna 1 or the second bowtie antenna 3. The first bowtie antenna 1 partially covers one end of the graphene layer 2, and the second bowtie antenna 3 partially covers the other end of the graphene layer 2; an insulating dielectric layer 4 is provided on the side of the graphene layer 2 away from the asymmetric bowtie antenna; the gate metal electrode layer 5 is provided on the side of the insulating dielectric layer 4 away from the graphene layer 2; the substrate layer 6 is provided on the side of the gate metal electrode layer 5 away from the insulating dielectric layer 4.

[0037] Graphene has excellent electrical conductivity. After being combined with other materials, the conductivity of the heterojunction can be regulated, such as regulating the bandgap size, enhancing the carrier transport performance, etc. The effective detection layer of the gated asymmetric bowtie antenna graphene terahertz detector provided in the present application is a terahertz wave detector that uses a combination structure of a graphene layer 2, an asymmetric bowtie antenna, and a gate metal electrode layer 5 to detect terahertz waves.

[0038] During the terahertz wave detection process, the terahertz wave irradiates on the first bowtie antenna 1 and the second bowtie antenna 3, generating a hot spot effect. A current signal or a voltage signal is obtained on the asymmetric bowtie antenna. The voltage signal or the current signal generates hot carriers through in-band excitation within the graphene layer 2. The graphene hot carriers are cooled by the acoustic phonons of the graphene. After the graphene electrons absorb the terahertz wave, a temperature gradient is rapidly formed and the temperature difference from the metal lattice is maintained within the electron-phonon relaxation time. Under the action of this non-equilibrium electron temperature gradient, the graphene electrons generate a directional flow to form a measurable photocurrent. The asymmetric bowtie antenna includes the first bowtie antenna 1 and the second bowtie antenna 3. A plurality of hollow structures for amplifying the thermo-photoelectric effect of the asymmetric bowtie antenna are provided in the middle of the first bowtie antenna 1 or the second bowtie antenna 3. One end of the first bowtie antenna 1 partially covers the graphene layer 2, and the other end of the second bowtie antenna 3 partially covers the graphene layer 2 and is electrically connected to the graphene layer 2. Due to the asymmetry of the asymmetric bowtie antenna, the temperatures at both ends are different. Different temperature gradients generate a photo-voltage difference under the influence of the thermo-photoelectric effect, obtaining a current signal or a voltage signal. Applying a voltage on the gate metal electrode layer 5 can change the magnitude and polarity of the voltage signal or the current signal. For example, Figure 3 shows a schematic diagram of the photocurrent response magnitude of the gated asymmetric bowtie antenna graphene terahertz detector under different gate voltages when irradiated by a 2.52 THz laser. When the terahertz signal polarization is parallel to the asymmetric bowtie antenna, the maximum photocurrent response signal can be generated. For example, Figure 4 is a schematic diagram of the ratio of the photocurrent response to the maximum photocurrent response magnitude of the gated asymmetric bowtie antenna graphene terahertz detector provided by a preferred embodiment of the present invention under irradiation by a 2.52 THz laser at different polarization angles. For example, Figure 5 is the graphene Raman scattering spectrum of the gated asymmetric bowtie antenna graphene terahertz detector.

[0039] The thermo-photoelectric effect is a representative optoelectronic response mechanism in the gated asymmetric bowtie antenna graphene terahertz detector provided in this application. Since the energy of the terahertz wave is at the meV level, which is much smaller than the energy of inter-band excitation, the voltage signal or current signal generated by the asymmetric bowtie antenna generates hot carriers through in-band excitation within the graphene layer 2. At the same time, the small Fermi surface and the law of conservation of momentum limit the scattering of electrons by acoustic phonons, that is, the scattering between electrons and phonons in the graphene layer 2 is weak, while the scattering between electrons and electrons is relatively strong. The interaction between graphene electrons and electrons is also shorter than the interaction between electrons and phonons. Since the electron heat capacity of graphene is much smaller than the lattice heat capacity, electrons rapidly form a temperature gradient after absorbing the terahertz wave and maintain the temperature difference from the lattice within the electron-phonon relaxation time. Under the action of this temperature difference, electrons generate a directional flow to form a measurable photocurrent, enabling the theoretical limit response speed of the gated asymmetric bowtie antenna graphene terahertz detector in this application to reach the picosecond (PS) level.

[0040] In a preferred embodiment of the present application, the thickness dimension range of the graphene layer 2 is 1 μm - 500 μm. A single-layer graphene layer or a multi-layer graphene layer can be selected. The single-layer graphene layer has an extremely high electron mobility, which further improves the response magnitude of the graphene terahertz detector with a gated asymmetric bowtie antenna provided by the present application. According to actual needs, the parameters of the graphene layer 2 are adjusted, such as the number of layers of the graphene layer 2, the doping polarity and concentration, to optimize the performance of the terahertz wave detector specifically, so as to improve the response magnitude of terahertz wave detection and enhance the sensitivity and stability of the graphene terahertz detector with a gated asymmetric bowtie antenna.

[0041] In a preferred embodiment of the present application, the graphene layer 2 can also adopt a graphene-molybdenum disulfide heterostructure. The graphene-molybdenum disulfide heterostructure is a vertical van der Waals heterostructure composed of graphene and molybdenum disulfide in transition metal dichalcogenides. Both graphene and molybdenum disulfide are two-dimensional layered materials. When they are combined in the form of a heterostructure, new interfaces and energy band structures can be formed, thus exhibiting unique electrical and optical properties. For example, under photoexcitation, charge transfer occurs between graphene and molybdenum disulfide to enhance the photoelectric response and energy conversion efficiency. The addition of molybdenum disulfide can further improve the response magnitude of the graphene terahertz detector with a gated asymmetric bowtie antenna.

[0042] In a preferred embodiment of the present application, when a terahertz wave signal irradiates on the asymmetric bowtie antenna, a current signal or a voltage signal can be obtained on the asymmetric bowtie antenna. A voltage is applied on the gate metal electrode layer to change the magnitude and polarity of the voltage signal or current signal, and to regulate the response magnitude of the graphene terahertz detector with a gated asymmetric bowtie antenna to the terahertz wave. The bowtie antenna itself has the characteristic of a wide frequency band. The asymmetric design makes the hot carriers generated by the photothermoelectric effect of the two bowties different, further causing different photocurrents or photovoltages to be generated at both ends of the asymmetric bowtie antenna, and further improving the response magnitude of the graphene terahertz detector with a gated asymmetric bowtie antenna to terahertz wave detection.

[0043] In a preferred embodiment of the present application, as Figure 2 shown, one of the bowties of the asymmetric bowtie antenna is a complete sector, and the other bowtie is also a sector, but several hollow structures for amplifying the photothermoelectric effect are provided in the middle. The sector antenna has a wide beam angle and can cover a large area. The asymmetric design can further optimize the beam pattern of the antenna, making it have stronger polarization measurement performance.

[0044] In a preferred embodiment of the present application, the number of the hollow structures is greater than or equal to 1. The number of the hollow structures can be set according to needs and the shape of the hollow structures, so that the graphene terahertz detector with a gated asymmetric bowtie antenna has a larger response magnitude.

[0045] The fan-shaped design of the asymmetric bowtie antenna has a smaller volume and weight, making it more convenient for installation and maintenance. Especially in an environment with limited space, the compact structure is particularly important.

[0046] The choice of the thickness of the asymmetric bowtie antenna will cause changes in the antenna's response at different frequencies, thereby affecting its bandwidth. The thickness selection of the asymmetric bowtie antenna should help maintain the stable performance of the antenna within the desired frequency range. In the preferred embodiment of this application, the thickness dimension range of the asymmetric bowtie antenna is 0.001μm - 2μm. This thickness range enables the asymmetric bowtie antenna to have high stability and a large response size in the terahertz band.

[0047] The material used for the asymmetric bowtie antenna also has an important impact on its performance. In the preferred embodiment of this application, the asymmetric bowtie antenna is a single material of any one of Al, Ag, Au, Bi, Cr, Ti, Ni, and ionic gel, or a composite material composed of at least two of Al, Ag, Au, Bi, Cr, Ti, Ni, and ionic gel. Al, Ag, Au, Bi, Cr, Ti, Ni, and ionic gel all have good electrical conductivity and mechanical properties, which can further improve the stability of the gated asymmetric bowtie antenna graphene terahertz detector provided in this application.

[0048] In the preferred embodiment of this application, a ring patch is arranged in the bowtie slot of the asymmetric bowtie antenna. The bowtie slot is located in the central region of the asymmetric bowtie antenna and is shaped like an open bowtie or butterfly knot. The ring patch can generate a specific radiation pattern, which combines with the main radiator of the asymmetric bowtie antenna to optimize the radiation pattern and gain of the antenna. The ring patch can introduce additional resonant modes, thereby increasing the bandwidth of the antenna. The resonant modes introduced by the ring patch can be coupled with the main resonant mode of the asymmetric bowtie antenna to form a wider operating frequency band. The size and shape of the ring patch can be conveniently adjusted to achieve fine tuning of the antenna's resonant frequency, enabling the gated asymmetric bowtie antenna graphene terahertz detector provided in this application to maintain stable performance within a wider frequency range.

[0049] In the preferred embodiment of this application, the asymmetric bowtie antenna further includes an asymmetric coplanar waveguide feeding structure, which is connected to the bowtie slot. By optimizing the feeding structure, the asymmetric coplanar waveguide feeding structure can significantly increase the bandwidth of the asymmetric bowtie antenna. This design not only improves the radiation efficiency of the asymmetric bowtie antenna but also increases the frequency adaptability, enabling the asymmetric bowtie antenna to perform seamless communication within a wider frequency band, thereby further improving the response size and stability of the gated asymmetric bowtie antenna graphene terahertz detector disclosed in this application.

[0050] In a preferred embodiment of the present application, an insulating dielectric layer 4 is provided on the side of the graphene layer 2 away from the asymmetric bowtie antenna; a gate metal electrode layer 5 is provided on the side of the insulating dielectric layer 4 away from the graphene layer 2; a substrate layer 6 is provided on the side of the gate metal electrode layer 5 away from the insulating dielectric layer 4. Based on the voltage of the gate metal electrode layer 5, the Fermi level of graphene is regulated, and at the same time, the photothermal electric effect of the gated asymmetric bowtie antenna graphene terahertz detector is regulated, so as to change the polarity and magnitude of the photocurrent or photovoltage of the gated asymmetric bowtie antenna graphene terahertz detector.

[0051] In a preferred embodiment of the present application, the material of the insulating dielectric layer 4 is any one of single materials such as SiO2, Al2O3, HfO2, Si3N4, MgO, MnO2, h-BN, diamond, mica and polymer material films, or a composite material composed of at least two of SiO2, Al2O3, HfO2, Si3N4, MgO, MnO2, h-BN, diamond, mica and polymer material films, and has good insulation performance.

[0052] In a preferred embodiment of the present application, the substrate layer 6 is any one of single materials such as polymer flexible films, intrinsic semiconductor materials and doped semiconductor materials containing other elements, or a composite material composed of at least two of polymer flexible films, intrinsic semiconductor materials and doped semiconductor materials containing other elements, and the thickness of the substrate layer 6 is less than or equal to 1000 μm.

[0053] In a preferred embodiment of the present application, the insulating dielectric layer 4 can also be provided on the side of the graphene layer 2 close to the asymmetric bowtie antenna. Correspondingly, the gate metal electrode layer 5 is provided on the side of the insulating dielectric layer 4 away from the graphene layer 2, and the substrate layer 6 is provided on the side of the gate metal electrode layer 5 away from the insulating dielectric layer 4. This structure can also regulate the Fermi level of graphene based on the voltage of the gate metal electrode layer 5, and at the same time regulate the photothermal electric effect of the gated asymmetric bowtie antenna graphene terahertz detector, so as to change the polarity and magnitude of the photocurrent or photovoltage of the gated asymmetric bowtie antenna graphene terahertz detector.

[0054] Correspondingly, in a preferred embodiment of the present application, based on the gated asymmetric bowtie antenna graphene terahertz detector of the present application, the embodiment of the present application also provides a preparation method of the gated asymmetric bowtie antenna graphene terahertz detector for preparing the gated asymmetric bowtie antenna graphene terahertz detector disclosed in the embodiment of the present application, as Figure 6 shown, the method includes:

[0055] S1. Perform sputtering, deposition or evaporation treatment on one surface of the obtained substrate layer to form a gate metal electrode layer;

[0056] S2. Perform oxidation and deposition processes on the surface of the substrate where the gate metal electrode layer is prepared to form an insulating dielectric layer;

[0057] S3. Transfer a graphene layer to the side of the insulating dielectric layer away from the substrate to obtain a graphene layer;

[0058] S4. Perform photolithography, sputtering, deposition, or evaporation processes on two opposite ends of the graphene layer to form an asymmetric bowtie antenna, so as to obtain the gate-controlled asymmetric bowtie antenna graphene terahertz detector.

[0059] For the specific limitations on the preparation method of a gate-controlled asymmetric bowtie antenna graphene terahertz detector, reference can be made to the above limitations on a gate-controlled asymmetric bowtie antenna graphene terahertz detector, which will not be elaborated here. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0060] A gate-controlled asymmetric bowtie antenna graphene terahertz detector and a preparation method provided in this embodiment are used to solve the technical problem of how to design a terahertz wave detector to achieve efficient detection of broadband terahertz waves under room temperature conditions. Among them, it includes a graphene layer, an asymmetric bowtie antenna, an insulating dielectric layer, a gate metal electrode layer, and a substrate layer; the asymmetric bowtie antenna is electrically connected to the graphene layer and includes a first bowtie antenna and a second bowtie antenna. A plurality of hollow structures for amplifying the thermophotovoltaic effect are provided in the middle of the first bowtie antenna or the second bowtie antenna. The first bowtie antenna partially covers one end of the graphene layer, and the second bowtie antenna partially covers the other end of the graphene layer; an insulating dielectric layer is provided on the side of the graphene layer away from the asymmetric bowtie antenna; the gate metal electrode layer is provided on the side of the insulating dielectric layer away from the graphene layer; the substrate layer is provided on the side of the gate metal electrode layer away from the insulating dielectric layer. The graphene terahertz wave detector provided in this application uses the graphene layer, the asymmetric bowtie antenna, and the gate metal electrode layer as effective detection parts to effectively improve the response size of the graphene terahertz wave detector at room temperature and achieve polarization detection.

[0061] Each embodiment in this specification is described in a progressive manner. For parts that are directly the same or similar in each embodiment, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the method embodiment, since it is basically similar to the system embodiment, the description is relatively simple, and for the relevant parts, reference can be made to the description of the system embodiment. It should be noted that the technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combinations of these technical features do not conflict, they should all be considered to be within the scope described in this specification.

[0062] The above-described embodiments merely represent several preferred embodiments of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the scope of the patented application. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present application, several improvements and substitutions can be made, and these improvements and substitutions should also be regarded as the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the protection scope of the claimed rights.

Claims

1. A gated asymmetric bowtie antenna graphene terahertz detector, characterized in that, It includes a graphene layer, an asymmetric bowtie antenna, an insulating dielectric layer, a gate metal electrode layer, and a substrate layer; The asymmetric bowtie antenna is electrically connected to the graphene layer and includes a first bowtie antenna and a second bowtie antenna. A plurality of hollow structures for amplifying the thermophotovoltaic effect are provided in the middle of the first bowtie antenna or the second bowtie antenna. The first bowtie antenna partially covers one end of the graphene layer, and the second bowtie antenna partially covers the other end of the graphene layer; The insulating dielectric layer is provided on the side of the graphene layer away from the asymmetric bowtie antenna; The gate metal electrode layer is provided on the side of the insulating dielectric layer away from the graphene layer; The substrate layer is provided on the side of the gate metal electrode layer away from the insulating dielectric layer; The asymmetric bowtie antenna is a single material of any one of Al, Ag, Bi, Cr, Ni, and ionic gel; or, the asymmetric bowtie antenna is a composite material composed of at least two of Al, Ag, Bi, Cr, Ni, and ionic gel; A ring patch is provided in the bowtie groove of the asymmetric bowtie antenna; The thickness range of the graphene layer is 1 μm - 500 μm; The graphene layer is a graphene-molybdenum disulfide heterostructure; The asymmetric bowtie antenna further includes an asymmetric coplanar waveguide feeding structure connected to the bowtie groove.

2. The gated asymmetric bowtie antenna graphene terahertz detector according to claim 1, wherein The hollow structure is fan-shaped.

3. The gated asymmetric bowtie antenna graphene terahertz detector according to claim 1, wherein The number of the hollow structures is greater than or equal to 1.

4. The gated asymmetric bowtie antenna graphene terahertz detector according to claim 1, wherein The thickness dimension range of the asymmetric bowtie antenna is 0.001 μm - 2 μm.

5. The gated asymmetric bow-tie antenna graphene terahertz detector according to claim 1, wherein, The graphene layer is single-layer or multi-layer graphene.

6. The gated asymmetric bowtie antenna graphene terahertz detector according to claim 1, characterized in that The insulating dielectric layer is a single material of any one of SiO2, Al2O3, HfO2, Si3N4, MgO, MnO2, h-BN, diamond, mica, and polymer material thin films; or, the insulating dielectric layer is a composite material composed of at least two of SiO2, Al2O3, HfO2, Si3N4, MgO, MnO2, h-BN, diamond, mica, and polymer material thin films.

7. A preparation method of a gate-controlled asymmetric bowtie antenna graphene terahertz detector for preparing the gate-controlled asymmetric bowtie antenna graphene terahertz detector according to any one of claims 1-6, characterized in that, The preparation method includes: Performing a deposition process on one surface of the obtained substrate layer to form a gate metal electrode layer; Performing an oxidation and deposition process on the surface of the substrate provided with the gate metal electrode layer to form an insulating dielectric layer; Transferring a graphene layer on the side of the insulating dielectric layer away from the substrate to obtain a graphene layer. The thickness range of the graphene layer is 1 μm - 500 μm, and the graphene layer is a graphene-molybdenum disulfide heterostructure; Performing a deposition process on two opposite ends of the graphene layer to form an asymmetric bowtie antenna, so as to obtain the gate-controlled asymmetric bowtie antenna graphene terahertz detector. The asymmetric bowtie antenna is a single material of any one of Al, Ag, Au, Bi, Cr, Ti, Ni, and ionic gel, or, the asymmetric bowtie antenna is a composite material composed of at least two of Al, Ag, Au, Bi, Cr, Ti, Ni, and ionic gel. A ring patch is provided in the bowtie groove of the asymmetric bowtie antenna, and the asymmetric bowtie antenna further includes an asymmetric coplanar waveguide feeding structure connected to the bowtie groove.

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