Two-dimensional material terahertz detector based on integrated control of chiral helical antenna

Abstract

The two-dimensional material terahertz detector based on the integrated control of the chiral spiral antenna of the present invention, the detector structure from bottom to top: includes a silicon substrate, a silicon dioxide layer, a two-dimensional material, a source electrode, a drain electrode, an aluminum oxide film and a gate electrode, on the intrinsic silicon substrate is a silicon dioxide layer, on the silicon dioxide layer is prepared a two-dimensional material, at both ends of the two-dimensional material contact is a source electrode and a drain electrode, the aluminum oxide film covers the two-dimensional material, the source electrode and the drain electrode, on the aluminum oxide film is a gate electrode, the gate electrode is in the middle of the source electrode and the drain electrode, the two-dimensional material is used as the channel material of the device, the source electrode, the drain electrode and the gate electrode are selected from spiral-shaped planar metals to form an asymmetric spiral structure. The two-dimensional material terahertz detector based on the integrated control of the chiral spiral antenna of the present invention realizes controllable photocurrent direction, self-driven operation at room temperature, fast response speed and easy integration.

Description

Technical Field

[0001] The present invention belongs to the technical field of terahertz detection, and in particular relates to a two-dimensional material terahertz detector based on integrated control of a chiral spiral antenna. Background Art

[0002] Terahertz technology has shown great application potential in many fields such as communication, sensing and imaging. However, it is often difficult to achieve high power and high performance standards by relying on pure electronics or photonics to develop terahertz devices. This limitation has seriously slowed down the pace of terahertz band research and was even regarded as an insurmountable obstacle. The key to the successful application and breakthrough of terahertz technology lies in the development of detection and imaging systems that are both high-speed and highly sensitive and can work at room temperature. This requires us to develop room-temperature detection equipment that can enhance the interaction between light and devices, thereby improving the photoelectric response of terahertz waves. Unfortunately, traditional methods that rely on quantum well transitions have encountered major challenges in terahertz detection. The energy of terahertz photons is lower than the thermal perturbation energy, which makes saturation easy to occur. Despite the use of field effect transistor plasmon overdamped oscillation technology, the achieved response rate is still unsatisfactory. Therefore, it is urgent to explore new semiconductor materials and innovative functional structures to achieve effective terahertz wave detection. Two-dimensional materials have emerged as a new class of nanomaterials that have shown significant advantages over traditional bulk materials in the fields of electronics and optoelectronics. The unique electronic and optical properties of these materials are due to the quantum confinement effects brought about by their two-dimensional structure, which allows us to explore the interaction between light and matter at the nanoscale.

[0003] Although two-dimensional materials show great potential in the field of photons and optoelectronics, their weak light-matter interaction and high dark current levels limit the conversion efficiency or operating cutoff wavelength of photodetectors, thus restricting the practical application of two-dimensional material systems. Summary of the invention

[0004] The purpose of the present invention is to provide a two-dimensional material terahertz detector based on integrated control of a chiral spiral antenna in response to the problems in the prior art.

[0005] To this end, the above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0006] A two-dimensional material terahertz detector based on integrated control of a chiral spiral antenna, wherein the detector structure from bottom to top includes: a silicon substrate, a silicon dioxide layer, a two-dimensional material, a source electrode, a drain electrode, an aluminum oxide film and a gate electrode, wherein a silicon dioxide layer is formed on the intrinsic silicon substrate, a two-dimensional material is prepared on the silicon dioxide layer, a source electrode and a drain electrode are in contact at both ends of the two-dimensional material, an aluminum oxide film covers the two-dimensional material, the source electrode and the drain electrode, and a gate electrode is formed on the aluminum oxide film, wherein the gate electrode is located in the middle of the source electrode and the drain electrode, and a two-dimensional material is used as a channel material of the device, and a spiral-shaped planar metal is selected for the source, the drain and the gate to form an asymmetric spiral structure.

[0007] While adopting the above technical solutions, the present invention may also adopt or combine the following technical solutions:

[0008] As a preferred technical solution of the present invention: the silicon substrate is intrinsic high-resistance silicon, with a resistivity of 10000 Ω·cm and a thickness of 500 μm;

[0009] The silicon dioxide layer has a thickness of 300 nm;

[0010] The thickness of the two-dimensional material is 40 nm;

[0011] The thickness of the aluminum oxide film is 30 nm.

[0012] As a preferred technical solution of the present invention: in the asymmetric spiral structure composed of the source electrode, the drain electrode and the gate electrode, the metal thickness is 80nm and the channel size is 12μm; the inner radius and outer radius of the inner spiral of the spiral structure are 9.5μm and 99.5μm respectively, and the inner radius and outer radius of the outer spiral are 17.5μm and 107.5μm respectively.

[0013] As a preferred technical solution of the present invention: the source, drain and gate are made of a left-handed spiral planar metal, or a right-handed spiral planar metal.

[0014] Compared with the prior art, the two-dimensional material terahertz detector based on integrated control of a chiral spiral antenna of the present invention has the following beneficial effects: utilizing the combination of two-dimensional materials and a chiral asymmetric spiral antenna, utilizing the chiral asymmetric spiral structure, adjusting the position of the gate at the center of the channel and replacing different contact metals of the source and drain electrodes, so as to achieve the purpose of enhancing or weakening the asymmetry of the local electric field, further utilizing the electrostatic field generated by applying the gate voltage to control the carrier concentration in the two-dimensional material channel, controlling the direction and magnitude of the photocurrent, and realizing fast and sensitive terahertz detection.

[0015] The two-dimensional material terahertz detector based on integrated control of a chiral spiral antenna of the present invention demonstrates a universal control method for terahertz light-induced hot carrier effects through the asymmetric coupling effect driven by the spiral antenna. The design of the spiral antenna and the strong light-matter interaction of the asymmetric electric field result in a higher response rate and a faster response speed, achieving controllable photocurrent direction, self-driven operation at room temperature, fast response speed and easy integration, etc., and can be used for compact multifunctional terahertz detectors that work at room temperature and are suitable for long wavelengths. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a side view schematic diagram of a two-dimensional material terahertz detector based on integrated control of a chiral spiral antenna according to the present invention;

[0017] Figure 2 A top view of the structure of a two-dimensional material terahertz detector with integrated control of a right-handed spiral antenna;

[0018] Figure 3 A top view of the structure of a two-dimensional material terahertz detector with integrated control of a left-handed spiral antenna;

[0019] Figure 4 The time-varying light response waveform of the two-dimensional material terahertz detector integrated and controlled by the right-handed spiral antenna at 0 V;

[0020] Figure 5 The time-varying light response waveform of the two-dimensional material terahertz detector integrated and controlled by the left-handed spiral antenna at 0 V;

[0021] Figure 6 The photocurrent response of the two-dimensional material terahertz detector integrated and controlled by the right-handed spiral antenna at 0.12 THz and different bias voltages (-200V to 200V) with the gate voltage changing (-3V to 3V);

[0022] Figure 7 The photocurrent response of the two-dimensional material terahertz detector integrated and controlled by the left-handed spiral antenna at 0.12 THz and different bias voltages (-100V to 100V) with the gate voltage changing (-3V to 3V);

[0023] Figure 8 The response time of the two-dimensional material terahertz detector based on the integrated control of the chiral spiral antenna of the present invention;

[0024] Fig. 9 It is the noise equivalent power of the two-dimensional material terahertz detector based on the integrated control of the chiral spiral antenna of the present invention;

[0025] Fig.10 The photocurrent response of the two-dimensional material terahertz detector based on the integrated control of the chiral spiral antenna of the present invention changes with different incident light power densities. DETAILED DESCRIPTION

[0026] The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

[0027] The present invention discloses a two-dimensional material terahertz detector based on integrated control of a chiral spiral antenna and a preparation method thereof. The two-dimensional material and the chiral asymmetric spiral antenna are combined, and the asymmetric spiral structure of the chirality is utilized to adjust the position of the gate at the center of the channel and replace different contact metals of the source and drain electrodes to achieve the purpose of enhancing or weakening the asymmetry of the local electric field. Furthermore, the electrostatic field generated by applying a gate voltage is used to control the carrier concentration in the two-dimensional material channel, so that the direction and size of the photocurrent can be controlled to achieve fast and sensitive terahertz detection.

[0028] The present invention refers to a two-dimensional material terahertz detector based on integrated control of a chiral spiral antenna. The two-dimensional material includes black phosphorus or graphene, and the detector structure from bottom to top includes: an intrinsic silicon substrate 1, a silicon dioxide layer 2, a two-dimensional material 3, a source electrode 4, a drain electrode 5, an aluminum oxide film 6 and a gate electrode 7.

[0029] A silicon dioxide layer 2 is provided on an intrinsic silicon substrate 1, a two-dimensional material 3 is prepared on the silicon dioxide layer 2, a source electrode 4 and a drain electrode 5 are contacted at both ends of the two-dimensional material 3, an aluminum oxide film 6 covers the two-dimensional material 3, the source electrode 4 and the drain electrode 5, and a gate electrode 7 is provided on the aluminum oxide film 6, and the gate electrode 7 is located in the middle position between the source electrode 4 and the drain electrode 5. Based on the above characteristics, right-handed spiral and left-handed spiral structures are designed respectively, and the two spiral structures have chiral characteristics.

[0030] The preferred technical solution of the present invention is as follows: the silicon substrate 1 is intrinsic high-resistance silicon with a resistivity of 10000 Ω·cm and a thickness of 500 μm; the covering 1 is a silicon dioxide layer 2 with a thickness of 300 nm; the two-dimensional material 5 is 40 nm thick; the aluminum oxide film 6 is 30 nm thick; the source electrode 4, the drain electrode 5 and the gate electrode 7 form an asymmetric spiral structure, the metal thickness is 80 nm, and the channel size is 12 μm; the inner radius and outer radius of the inner spiral of the spiral structure are 9.5 μm and 99.5 μm respectively, and the inner radius and outer radius of the outer spiral are 17.5 μm and 107.5 μm respectively.

[0031] The method for preparing a two-dimensional material terahertz detector based on integrated control of a chiral spiral antenna of the present invention comprises the following steps:

[0032] (1) Using acetone, anhydrous ethanol and deionized water to ultrasonically clean the surface of the silicon substrate covered with silicon dioxide;

[0033] (2) Using dry transfer technology, two-dimensional materials (such as black phosphorus or graphene) are mechanically exfoliated using blue tape and then transferred to a high-resistance silicon substrate;

[0034] (3) using a hot plate to bake the photoresist AZ5214 attached to the substrate;

[0035] (4) Using a combination of UV lithography, electron beam evaporation and lift-off processes to prepare pre-designed spiral structured source and drain electrodes;

[0036] (5) Depositing an aluminum oxide film by an atomic layer deposition process to obtain a top gate dielectric layer;

[0037] (6) Using a combination of UV lithography, electron beam evaporation and lift-off techniques to prepare a pre-designed spiral gate structure;

[0038] (7) A two-dimensional material (black phosphorus or graphene, etc.) transistor with integrated spiral antenna is attached to a PCB base and wired to form a two-dimensional material (black phosphorus or graphene, etc.) terahertz detector with integrated spiral antenna.

[0039] The present invention has the following beneficial effects: The present invention is based on a two-dimensional material terahertz detector integrated and controlled by a chiral spiral antenna and a preparation method thereof, which uses the strong asymmetry introduced by the Archimedean spiral field coupling and plays a key role in the photocurrent response generated when the photon energy is far below the band gap of the two-dimensional material. The light response is amplified by the strong interaction between different spiral fingers (as source, gate and drain), and the asymmetry depends on the spiral finger spacing and chirality. By changing the metal contact of the drain and source, an order of magnitude increase in the light response can be obtained. The design of the spiral antenna and the strong light-matter interaction of the asymmetric electric field make the response rate higher and the response speed faster.

[0040] The present invention discloses a two-dimensional material (black phosphorus or graphene, etc.) terahertz detector based on integrated control of a chiral spiral antenna and a preparation method thereof, which demonstrates a universal control method of the terahertz light-induced hot carrier effect through the asymmetric coupling effect driven by the chiral spiral antenna. In the present invention, a two-dimensional material (black phosphorus or graphene) is used as the channel material of the device, and a spiral-shaped planar metal antenna is used as the source, drain and gate to prepare a terahertz detector with left-handed and right-handed spiral antennas. By designing the chirality and symmetry of the spiral structure, the direction and size of the photocurrent are successfully controlled, and fast and sensitive terahertz detection is achieved. The present invention provides an effective strategy for developing compact multifunctional terahertz detectors that work at room temperature and are suitable for long wavelengths. Example 1

[0041] The intrinsic high-resistance silicon has a resistivity of 10000 Ω·cm and a thickness of 500 μm; the silicon dioxide layer is 300 nm thick; the two-dimensional material is 40 nm thick; the aluminum oxide film is 30 nm thick; the source electrode, drain electrode and gate electrode form an asymmetric spiral structure, the metal thickness is 80 nm and the channel size is 12 μm; the inner radius and outer radius of the inner spiral of the spiral structure are 9.5 μm and 99.5 μm respectively, and the inner radius and outer radius of the outer spiral are 17.5 μm and 107.5 μm respectively. Figure 4 and Figure 5 The time-resolved photoresponse of right-handed and left-handed spiral structure detectors without bias voltage was demonstrated. Devices with two different spiral directions showed opposite photocurrent responses. The device exhibited self-powered characteristics at room temperature and presented a fast and stable response waveform. The results show that the terahertz detector of two-dimensional materials (black phosphorus or graphene, etc.) with integrated control of chiral spiral antennas provided by the present invention can control the direction and size of photocurrent, and the method of improving the detection capability of the device is reasonable and effective. Example 2

[0042] The intrinsic high-resistance silicon has a resistivity of 10000 Ω·cm and a thickness of 500 μm; the silicon dioxide layer is 300 nm thick; the two-dimensional material is 40 nm thick; the aluminum oxide film is 30 nm thick; the source electrode, drain electrode and gate electrode form an asymmetric spiral structure, the metal thickness is 80 nm and the channel size is 12 μm; the inner radius and outer radius of the inner spiral of the spiral structure are 9.5 μm and 99.5 μm respectively, and the inner radius and outer radius of the outer spiral are 17.5 μm and 107.5 μm respectively. Figure 6 Demonstrated the photocurrent response of the two-dimensional material terahertz detector with integrated control of the right-handed spiral antenna at 0.12 THz and different bias voltages (-200V to 200V) with gate voltage changes (-3V to 3V); Figure 7 The photocurrent response of the two-dimensional material terahertz detector with integrated left-handed spiral antenna control at 0.12 THz and different bias voltages (-100V to 100V) with gate voltage changes (-3V to 3V) is demonstrated. Through gate voltage control, the two devices with different spiral directions also show opposite photocurrent responses. The results show that the two-dimensional material (black phosphorus or graphene, etc.) terahertz detector with integrated chiral spiral antenna control provided by the present invention can control the size of photocurrent and broaden the light response range, and the method of improving the sensitivity of the device is reasonable and effective. Example 3

[0043] The intrinsic high-resistance silicon has a resistivity of 10,000 Ω·cm and a thickness of 500 μm; the silicon dioxide layer is 300 nm thick; the two-dimensional material is 40 nm thick; the aluminum oxide film is 30 nm thick; the source electrode, drain electrode, and gate electrode form an asymmetric spiral structure, the metal thickness is 80 nm, and the channel size is 12 μm; the inner radius and outer radius of the inner spiral of the spiral structure are 9.5 μm and 99.5 μm, respectively, and the inner radius and outer radius of the outer spiral are 17.5 μm and 107.5 μm, respectively. The direct photoelectric conversion method based on hot electrons avoids the influence of lattice heat dissipation, thereby achieving a high response speed. The response time of the detector is about 6 μs for the rising edge and about 8 μs for the falling edge. Figure 8 As shown. 1 / f noise, shot noise and thermal Johnson-Nyquist noise are the main noise sources of the detector. The self-driven photoresponse of the spiral structure detector does not require source-drain voltage, and the impact of shot noise can be ignored. 1 / f noise shows that the power spectral density decreases with increasing frequency. Fig. 9 The noise equivalent power is shown to be about 1.95×10 at 0.30 THz. -10 W / Hz 0.5 , without considering any external bias conditions. Fig.10 The time-resolved photoresponse changes of the device were studied under terahertz radiation with different power densities. The results showed that the device has fast switching capability, stable self-driven photocurrent and excellent signal-to-noise ratio.

[0044] The present invention demonstrates a universal control method for terahertz light-induced hot carrier effect through the asymmetric coupling effect driven by spiral antennas. Using spiral-shaped planar metal antennas as source, drain and gate, terahertz detectors with left-handed and right-handed spiral antennas are prepared.

[0045] The present invention discloses a two-dimensional material (black phosphorus or graphene, etc.) terahertz detector based on integrated control of a chiral spiral antenna and a preparation method thereof. The steps of preparing the device include transferring a mechanically peeled two-dimensional material (black phosphorus or graphene, etc.) to a high-resistance silicon substrate, using ultraviolet lithography or electron beam exposure technology to make a source and a drain, growing an aluminum oxide dielectric layer by atomic layer deposition technology, and then using ultraviolet lithography or electron beam exposure technology to make a gate, and finally using an electron beam evaporation process to prepare a metal electrode, thereby forming a two-dimensional material terahertz detector with a chiral spiral structure. The device structure is as follows from bottom to top: the bottom layer is an intrinsic silicon substrate, the second layer is a silicon dioxide oxide layer, the third layer is a two-dimensional material (black phosphorus or graphene, etc.) and a spiral antenna mounted on the two-dimensional material and a metal electrode on the antenna. By using an asymmetric chiral spiral structure, the asymmetry of the local electric field is enhanced or weakened by adjusting the position of the gate at the center of the channel and replacing different contact metals of the source and drain electrodes. Furthermore, by using the electrostatic field generated by applying a gate voltage to regulate the carrier concentration in the two-dimensional material channel, the direction and magnitude of the photocurrent can be controlled, and fast and sensitive terahertz detection can be achieved. The advantages of the present invention are controllable photocurrent direction, self-driven operation at room temperature, fast response speed and easy integration, etc., and it can be used to develop compact multifunctional terahertz detectors that work at room temperature and are suitable for long wavelengths.

[0046] The above-mentioned specific implementation methods are used to explain the present invention and are only preferred embodiments of the present invention, rather than limiting the present invention. Any modifications, equivalent substitutions, improvements, etc. made to the present invention within the spirit of the present invention and the protection scope of the claims shall fall within the protection scope of the present invention.

Claims

1. Two-dimensional material terahertz detector based on integrated control of chiral helical antenna, characterized by: The detector structure from bottom to top includes: a silicon substrate, a silicon dioxide layer, a two-dimensional material, a source electrode, a drain electrode, an aluminum oxide film and a gate electrode. The silicon dioxide layer is on the intrinsic silicon substrate, and the two-dimensional material is prepared on the silicon dioxide layer. The source electrode and the drain electrode are in contact at both ends of the two-dimensional material. The aluminum oxide film covers the two-dimensional material, the source electrode and the drain electrode. The gate electrode is on the aluminum oxide film, and the gate electrode is located in the middle of the source electrode and the drain electrode. The two-dimensional material is used as the channel material of the device, and the source, drain and gate are made of spiral-shaped planar metal to form an asymmetric spiral structure.

2. The two-dimensional material terahertz detector based on integrated control of chiral helical antenna according to claim 1, characterized in that: The silicon substrate is intrinsic high-resistance silicon with a resistivity of 10000 Ω·cm and a thickness of 500 μm; The silicon dioxide layer has a thickness of 300 nm; The thickness of the two-dimensional material is 40 nm; The thickness of the aluminum oxide film is 30 nm.

3. The two-dimensional material terahertz detector based on integrated control of chiral helical antenna according to claim 1, characterized in that: In the asymmetric spiral structure composed of source electrode, drain electrode and gate electrode, the metal thickness is 80nm and the channel size is 12μm; the inner radius and outer radius of the inner spiral of the spiral structure are 9.5μm and 99.5μm respectively, and the inner radius and outer radius of the outer spiral are 17.5μm and 107.5μm respectively.

4. The two-dimensional material terahertz detector based on integrated control of chiral helical antenna according to claim 1, characterized in that: The source, drain and gate are made of a left-handed spiral planar metal, or a right-handed spiral planar metal.

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