Tantalum-nickel-selenium intermediate infrared detector based on microstructure regulation and control and application of tantalum-nickel-selenium intermediate infrared detector

Abstract

According to the tantalum-nickel-selenium intermediate infrared detector based on microstructure regulation and control, a silicon dioxide layer is arranged on an intrinsic high-resistance silicon substrate, a plasmon microstructure and a grating structure are arranged on the silicon dioxide layer, and the grating structure and the plasmon microstructure are arranged at an interval. The plasmon microstructure and the grating structure are covered with a tantalum-nickel-selenium nanosheet, and the tantalum-nickel-selenium nanosheet is covered with a hexagonal boron nitride nanosheet protective layer. According to the invention, energy band alignment of tantalum-nickel-selenium and gold is utilized, and a synergistic effect of mid-infrared absorption enhancement and asymmetric temperature distribution of a microstructure area is realized with a plasmon microstructure and a grating microstructure in the microstructure, so that efficient mid-infrared self-driven detection, high response speed, high efficiency and high-performance infrared detection are realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of medium-wave infrared detection, and in particular relates to a tantalum-nickel-selenium medium-infrared detector based on microstructure regulation and application thereof. Background Art

[0002] The mid-infrared band covers multiple transmission windows of the atmosphere, and has the advantages of long range, strong ability to penetrate haze, and good anti-interference. Therefore, it has a wide range of applications in civil and military fields such as biomedical imaging, environmental monitoring, industrial detection, infrared guidance, etc. However, due to the small photon energy in the mid-infrared band, there are many challenges in achieving high-precision and high-sensitivity detection and control. For example, in terms of mid-infrared detectors, traditional detectors based on semiconductor materials such as mercury cadmium telluride usually require low-temperature refrigeration, and face technical bottlenecks such as difficult preparation process, high cost, and large dark counts. As a result, the current mid-infrared detection has problems such as high noise, slow response speed, and inability to achieve high-resolution imaging. In terms of mid-infrared optical control devices. In recent years, the rise of two-dimensional materials has provided a new direction for mid-infrared detection. Black phosphorus, as a representative material, has great application potential in infrared photodetectors with its narrow band gap, high carrier mobility, and strong light-matter interaction. However, due to its stability in the air, it has been limited to the laboratory research stage. A new type of ternary sulfur layered compound tantalum nickel selenium Ta 2 NiSe 5 The layers are bonded by weak van der Waals forces, and the layers consist of two TaSe 6 Octahedral single chain and NiSe 4 The periodic zigzag chain composed of tetrahedral single chains unfolds. This unique chain structure produces strong planar anisotropy, which is different from conventional transition metal dichalcogenides TMDCs. 2 NiSe 5 The unique atomic and band structure of Ta gives it a direct narrow band gap that remains constant regardless of its thickness. 2 NiSe 5 Excellent light absorption efficiency and stability, studies have reported that Ta 2 NiSe 5 The broad spectrum of visible mid-infrared response, polarization sensitivity and anisotropy of the material.

[0003] Ta 2 NiSe 5 The photoelectric response of the detector mainly depends on the separation and transmission of photogenerated carriers. In the mid-infrared band, due to the low energy of photons, photogenerated carriers cannot be generated, resulting in a decrease in the detector's response. Self-driven photodetectors require that the material itself has a high photogenerated carrier mobility and low dark current. 2 NiSe 5In the absence of an external electric field, it is difficult for the base detector to achieve efficient photoelectric conversion and signal output, and it is impossible to realize self-driven photoelectric detection.

[0004] It can be seen that although 2 NiSe 5 It has excellent wide-spectrum detection capabilities, but its photoelectric response mechanism limits its ability to detect mid-infrared radiation, and it cannot achieve self-driven photoelectric detection, which will greatly reduce its prospects in various communications and imaging applications.

[0005] So how to solve the problem? 2 NiSe 5 The problem of medium-wave infrared detectors and providing a high response rate and self-driven detection capability are technical problems that need to be solved urgently by technicians in this field. Summary of the invention

[0006] The first object of the present invention is to provide a tantalum nickel selenium mid-infrared detector based on microstructure regulation in response to the problems in the prior art.

[0007] To this end, the above-mentioned purpose of the present invention is achieved through the following technical solutions: A tantalum nickel selenium mid-infrared detector based on microstructure regulation, characterized in that: a silicon dioxide layer is arranged on an intrinsic high-resistance silicon substrate, a plasmon microstructure is arranged on the silicon dioxide layer, and the whole is rectangular, the plasmon microstructure includes two cross-shaped plasmon microstructures, the two are arranged in an interdigitated shape with a spacing, and each cross-shaped plasmon microstructure is respectively connected to a first positive electrode and a first negative electrode; the cross-shaped plasmon metal microstructure includes a plurality of cross-shaped resonance structure units, which are uniformly distributed on the interdigitated structure; a grating structure is also arranged on the silicon dioxide layer, and the whole is rectangular, the grating structure and the plasmon microstructure are arranged with a spacing, the grating structure includes two grating microstructures, the two grating microstructures are arranged in an interdigitated shape with a spacing, and each grating microstructure is respectively connected to a second positive electrode and a second negative electrode; a tantalum nickel selenium nanosheet is covered on the plasmon microstructure and the grating structure, and the tantalum nickel selenium nanosheet is covered with a hexagonal boron nitride nanosheet protective layer; The plasmon microstructure and grating microstructure are composite metal structures, with gold as the upper metal. By aligning the energy bands of tantalum, nickel and selenium and gold in tantalum nickel and selenium nanosheets, the local resonance enhancement effect produced by the synergistic plasmon microstructure and the enhanced incident light coupling of the grating microstructure enhance the mid-infrared absorption of the detector, achieving enhanced mid-infrared response at room temperature and realizing mid-infrared self-driven detection at room temperature.

[0008] While adopting the above technical solutions, the present invention may also adopt or combine the following technical solutions: As a preferred technical solution of the present invention: the lower metal of the plasmon microstructure is chromium with a thickness of 10 nm, the upper metal is gold with a thickness of 50 nm, and the overall size is 30 μm×30 μm; The cross-shaped plasmon microstructure includes 6 cross-shaped plasmon columns, which are arranged in a finger-like form with a width of 0.2 μm and a spacing of 0.9µm. The cross-shaped resonance structure units are evenly distributed on each cross-shaped plasmon column. The dipole length of the plasmon of each cross-shaped resonance structure unit is 1.6 μm and the width is 0.1 μm. The structural period of the cross-shaped resonance structure unit is 2.5 μm.

[0009] As a preferred technical solution of the present invention: the grating structure is a chrome-gold composite structure, the lower metal is chrome, which serves as an adhesion layer with a thickness of 10 nm, the upper metal is gold with a thickness of 50 nm, and the overall size is 30 μm×30 μm; The grating microstructure includes 6 grating microcolumns, which are arranged in the form of fingers. Each grating microcolumn is rectangular, 0.2 μm wide, and has a period of 2.5 μm.

[0010] As a preferred technical solution of the present invention: the resistivity of the intrinsic high-resistance silicon substrate is>10000 Ω·cm and the thickness is 500 μm; The thickness of the silicon dioxide layer is 300 nm; The thickness of the tantalum-nickel-selenium nanosheet is 95 nm; The thickness of the hexagonal boron nitride nanosheet is 15 nm.

[0011] As a preferred technical solution of the present invention: the first positive electrode, the first negative electrode, the second positive electrode and the second negative electrode are chromium-gold composite electrodes, the lower metal is chromium, which serves as an adhesion layer with a thickness of 10nm, the upper metal is gold with a thickness of 50nm, and the overall size of the four contact electrodes is 100 μm×100 μm.

[0012] The second object of the present invention is to provide an application of a tantalum nickel selenium mid-infrared detector based on microstructure regulation in response to the problems in the prior art.

[0013] To this end, the above-mentioned purpose of the present invention is achieved through the following technical solutions: It is used in signal receivers to transmit target data streams, convert optical signals into electrical signals, and the signals are collected and read by preamplifiers, phase-locked amplifiers and oscilloscopes. Finally, they are decoded on the computer side to realize photocurrent collection, and key performance parameters such as response rate, response speed and self-driven detection are evaluated.

[0014] Compared with the prior art, the tantalum nickel selenium mid-infrared detector based on microstructure regulation and its application of the present invention have the following beneficial effects: under mid-infrared excitation, the energy band alignment of tantalum nickel selenium and gold is utilized, and the synergistic effect of mid-infrared absorption enhancement and asymmetric temperature distribution in the microstructure area is achieved with the plasmon microstructure and grating structure in the microstructure, which significantly improves the performance of the detector; the supersurface of the plasmon microstructure introduces a new photoelectric detection mechanism based on hot carrier injection, which realizes ultra-high-speed detection of low-energy photons and greatly improves the response speed; the interface charge transfer transition path in the strongly coupled gold / tantalum nickel selenium heterostructure is utilized to directly excite electrons to generate hot electrons, and through the mutual coupling of photoelectric and photothermal physical processes, at room temperature, efficient mid-infrared self-driven detection, high response speed, high efficiency, and high-performance infrared detection are achieved, which has great application prospects in the field of light detection technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A structural front view of a tantalum-nickel-selenium mid-infrared detector based on microstructure regulation according to the present invention; Figure 2 A top view of a tantalum-nickel-selenium mid-infrared detector based on microstructure regulation according to the present invention; Figure 3 Figure (a) is a schematic diagram of the size parameters of a cross-shaped resonance structure unit of a tantalum nickel selenium mid-infrared detector based on microstructure regulation of the present invention; Figure 3 Figure (b) is a schematic diagram of local size parameters of a grating structure of a tantalum nickel selenium mid-infrared detector based on microstructure regulation according to the present invention; Figure 4 The simulation results and experimental results of the absorptivity of the plasmon microstructure of a tantalum nickel selenium mid-infrared detector based on microstructure regulation at a wavelength of 3-6 μm of the present invention; Figure 5 The electric field intensity magnification and temperature distribution simulated under 4.6 um mid-infrared radiation of a plasmon microstructure unit of a tantalum nickel selenium mid-infrared detector based on microstructure regulation of the present invention; Figure 6 Figure (a) is an optical microscopic image of a tantalum nickel selenium mid-infrared detector based on microstructure regulation of the present invention. Figure 6 Figure (b) is a 4.6 um mid-infrared photocurrent scanning image of the plasmon microstructure and grating structure area of ​​a tantalum nickel selenium mid-infrared detector based on microstructure regulation under a bias voltage of 0.1 V; Figure 7The photocurrent magnitudes of the plasmon microstructure and grating structure of a tantalum nickel selenium mid-infrared detector based on microstructure regulation under a bias voltage of 0.1 V at 520 nm, 638 nm, 940 nm, 1064 nm, 1310 nm, 1550 nm and 4.6 um are shown in the figure. Figure 8 Figure (a) shows the 4.6 um mid-infrared response time of a plasmon microstructure of a tantalum nickel selenium mid-infrared detector based on microstructure regulation under a bias voltage of 0.1 V; Figure 8 Figure (b) shows the 4.6 um mid-infrared response time of the grating structure of a tantalum nickel selenium mid-infrared detector based on microstructure regulation under a bias voltage of 0.1 V; Fig. 9 The 4.6 um mid-infrared response rate of the plasmon microstructure and grating structure of a tantalum nickel selenium mid-infrared detector based on microstructure regulation under a bias voltage of 0.1 V varies with the incident power; Fig.10 Figure (a) is a 4.6 um mid-infrared photocurrent scanning image of a plasmon microstructure and a grating structure of a tantalum nickel selenium mid-infrared detector based on microstructure regulation of the present invention under a bias voltage of 0 V; Fig.10 Figure (b) shows the photocurrent distribution at the middle section of the 4.6 um mid-infrared photocurrent of the plasmon microstructure and grating structure of the tantalum nickel selenium mid-infrared detector based on microstructure regulation under 0 V bias; In the accompanying drawings, there are an intrinsic high-resistance silicon substrate 1, a silicon dioxide layer 2, a first positive electrode 3, a first negative electrode 4, a second positive electrode 5, a second negative electrode 6, a plasmon microstructure 7, a grating structure 8, a tantalum nickel selenium nanosheet 9, and a hexagonal boron nitride nanosheet 10. DETAILED DESCRIPTION

[0016] The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

[0017] The present invention relates to a tantalum nickel selenium mid-infrared detector based on microstructure regulation and its application. The tantalum nickel selenium detector can enhance the photoelectric performance of the device in the mid-wave infrared through microstructure. Combining the tantalum nickel selenium two-dimensional material with plasmons achieves high response rate, high degree of freedom, fast response and self-driven detection capabilities. At the same time, the combination of electromagnetic structure and light response material achieves the improvement of detection performance and the expansion of functions, providing an effective way to regulate the multifunctionality of two-dimensional photoelectric materials.

[0018] The present invention discloses a tantalum nickel selenium mid-infrared detector based on microstructure regulation, wherein a silicon dioxide layer 2 is disposed on an intrinsic high-resistance silicon substrate 1, four chromium-gold contact electrodes, a plasmon microstructure 7 and a grating structure 8 are disposed on the silicon dioxide layer 2, a tantalum nickel selenium nanosheet 9 is disposed above the plasmon microstructure 7 and the grating structure 8, a protective layer of hexagonal boron nitride nanosheet 10 is disposed above the tantalum nickel selenium nanosheet 9, a first positive electrode 3, a first negative electrode 4, a second positive electrode 5 and a second negative electrode 6 are connected to different circuits according to different functions for various photoelectric tests.

[0019] The intrinsic high-resistance silicon substrate high-resistance silicon layer 1 is intrinsic high-resistance silicon, with a resistivity of >10000 Ω·cm and a thickness of 500 μm; covered thereon is a silicon dioxide layer 2 with a thickness of 300 nm; The tantalum-nickel-selenium nanosheet 9 has a thickness of 95 nm; the hexagonal boron nitride nanosheet 10 has a thickness of 15 nm; The materials of the four contact electrodes, plasmon microstructure and grating microstructure are all chromium and gold. The lower metal layer is chromium, which serves as an adhesion layer with a thickness of 10 nm. The upper metal layer is gold with a thickness of 50 nm. The overall size of the four contact electrodes is 100 μm×100 μm, and the overall size of the plasmon microstructure area and the grating structure area is 30 μm×30 μm.

[0020] The tantalum-nickel-selenium mid-infrared detector based on microstructure regulation of the present invention is manufactured by the following technical scheme: Step 1: First, the surface of the silicon substrate covered with silicon dioxide is ultrasonically cleaned using acetone, isopropanol, ethanol and deionized water, and the substrate is cut into 1 cm × 1 cm samples using precision cutting technology; Step 2: Use hot plate baking and a coating machine to coat the photoresist AZ5350 evenly on the substrate; Step 3, preparing the pre-designed contact electrode by combining UV lithography, electron beam evaporation and traditional stripping process; Step 4: Use hot plate baking and glue coating by glue spreader to make PMMA 950K-A4 evenly adhere to the substrate with the contact electrode prepared; Step 5, preparing the designed plasmon microstructure and grating microstructure at the center of the contact electrode by combining electron beam exposure, electron beam evaporation and traditional lift-off process; Step 6: Through the transfer platform micro-area positioning method, using dry transfer technology, use blue adhesive tape to mechanically peel off the tantalum nickel selenium body material, and then transfer it to the top of the microstructure for numbering and positioning marking; Step 7: Using the transfer platform micro-area positioning method and dry transfer technology, hexagonal boron nitride is mechanically peeled off using blue adhesive tape, and then transferred to the tantalum nickel selenium nanosheets for numbering and positioning marking; Step eight, attach the tantalum-nickel-selenium silicon-based substrate with integrated microstructure regulation to the PCB base, wire it, and package it to complete a directly testable detection device for achieving enhanced mid-infrared response and self-driven rapid photoelectric detection at room temperature.

[0021] Among them, in steps five, six and seven, Raman spectroscopy, optical microscopy, atomic force microscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy are used to characterize the morphology, size and composition of metal microstructures, tantalum nickel selenium and hexagonal boron nitride samples.

[0022] The tantalum nickel selenium mid-infrared detector based on microstructure regulation of the present invention has a sufficiently fast transfer speed of less than 100 fs for hot electrons generated under mid-infrared excitation based on the energy band alignment of tantalum nickel selenium and gold and the synergistic effect of the microstructure, which effectively avoids the energy loss and response time extension caused by carrier relaxation and recombination, thereby achieving the improvement of mid-infrared response speed at room temperature.

[0023] Compared with the prior art, the present invention has the following beneficial effects: a tantalum nickel selenium mid-infrared detector based on microstructure regulation and its application, an asymmetric microstructure is prepared on a substrate by electron beam exposure and electron beam evaporation, the asymmetric microstructure includes a plasmon microstructure and a grating structure, the difference between the plasmon microstructure and the grating structure lies in the presence or absence of a dipole for realizing plasmon resonance, and mid-infrared absorption enhancement and asymmetric temperature distribution in the microstructure area are realized, and a new photoelectric detection mechanism based on hot carrier injection is introduced into the plasmon metasurface, which realizes ultra-high-speed detection of low-energy photons and greatly improves the response speed; at the same time, a room temperature stable, easy to cleave and narrow-bandgap tantalum nickel selenium two-dimensional material grown by chemical vapor deposition is used as a channel photosensitive medium, and its bandgap can be basically stably maintained at 0.36 as the material thickness changes. eV direct band gap, and the material is a layered material stacked by weak van der Waals interactions, and the layers are composed of periodic sawtooth wave chains. It is precisely because of this unique atomic structure that while maintaining stability, it is easy to appear in a relatively regular long strip during mechanical peeling, which is conducive to the integration and design of the device. Tantalum nickel selenium nanosheets are integrated at the microstructure using the transfer platform micro-area positioning method and dry transfer technology. The use of hexagonal boron nitride as a protective layer can further improve the stability of the device. A tantalum nickel selenium mid-infrared detector based on microstructure regulation of the present invention has a relatively simple structure and mature process. Under the regulation of the microstructure, the response rate and response speed of tantalum nickel selenium are greatly improved, and self-driven detection of mid-wave infrared at room temperature is realized. The combination of electromagnetic structure and light response material realizes the improvement of detection performance and the expansion of functions, and provides an effective way to regulate the multifunctionality of two-dimensional optoelectronic materials, enhance the mid-infrared response at room temperature, improve the mid-infrared response speed at room temperature, and realize mid-infrared self-driven detection at room temperature.

[0024] In the present invention, based on the band alignment and synergy of tantalum nickel selenium and metal cross-shaped plasmon microstructures, efficient mid-infrared self-driven detection is achieved through the mutual coupling of photoelectric and photothermal physical processes. In the present invention, when mid-infrared light is irradiated to the plasmon microstructure area, the microstructure triggers local surface plasmon resonance, greatly enhances the local electromagnetic field intensity and significantly improves the mid-infrared light absorption efficiency of tantalum nickel selenium in this area; under the enhanced light absorption, the photogenerated carrier density in the tantalum nickel selenium nanosheet increases rapidly, and at the same time, due to the band alignment and the thermal effect of the plasmon microstructure, the tantalum nickel selenium material produces obvious photothermal conversion in the cross-shaped microstructure area. This photothermal conversion causes a significant increase in temperature in the area, and forms a clear temperature gradient between the cross-shaped resonance structure unit area and other areas. The formation of the temperature gradient further drives the diffusion and drift process of hot carriers: hot electrons migrate from the high temperature area-cross-shaped resonance structure unit area to the low temperature area-non-microstructure area along the temperature gradient direction, thereby forming a stable thermoelectric field in the tantalum nickel selenium nanosheet. This thermoelectric field can drive the photogenerated carriers to move in a specific direction and generate detectable electrical signals between electrodes without an external power supply, thus realizing mid-infrared self-driven photoelectric detection.

[0025] In the present invention, the temperature difference of the response material is generated by the asymmetry of the microstructure, thereby realizing the self-driven detection of the device in the mid-infrared. The transfer time of hot electrons excited by plasmons is in the order of femtoseconds, which effectively improves the response speed. The advantages of the present invention include easy integration, high response rate, high degree of freedom, fast response and self-driven detection capability. At the same time, the combination of electromagnetic structure and light-responsive material realizes the improvement of detection performance and the expansion of functions, providing an effective way to regulate the multifunctionality of two-dimensional optoelectronic materials.

[0026] In the present invention, the staggered cross-shaped plasmon microstructure design provides a uniform distribution of the electric field, and the rectangular cross-finger structure provides more cross-shaped resonance structure unit gaps: 1. By increasing the cross-shaped resonance structure unit gaps, multiple parallel light response units are formed, providing a larger light incident area, enhancing the interaction between light and the plasmon microstructure, and improving the light capture efficiency. The tantalum nickel selenium material in the gap area is exposed to a higher intensity local electromagnetic field, making the light absorption more sufficient; 2. The wider gap makes the drift path of the photogenerated carriers shorter, while reducing the charge recombination probability, thereby improving the photoelectric conversion efficiency; 3. In the electrode gap, the local temperature gradient caused by the plasmon microstructure is more obvious, which promotes the rapid transfer of hot electrons and further improves the self-driving ability of the device; 4. The larger gap can effectively reduce the breakdown risk caused by the excessive concentration of the local electric field, and improve the service life of the device.

[0027] In the present invention, the rectangular structure of the grating structure has the following functions: 1) Enhance the coupling of incident light. The rectangular grating structure redistributes the path of the incident mid-infrared light through the Bragg diffraction effect, and guides more light energy to be concentrated near the cross-shaped plasmon structure. 2) Form light field modulation. The grating structure produces a diffraction enhancement effect at a specific wavelength, making the light field distribution more uniform, creating a better optical environment for the localized surface plasmon resonance (LSPR) of the cross-shaped plasmon microstructure.

[0028] The role of the cross-shaped resonance structure unit: 1) Localized surface plasmon resonance (LSPR), the cross-shaped resonant structure unit can produce significant local electromagnetic field enhancement in the mid-infrared band through precisely designed geometric dimensions: aspect ratio and period. 2) Carrier and hot electron management, under the action of enhanced local electric field, the cross-shaped resonant structure unit accelerates the generation and separation of photogenerated carriers, and at the same time improves the mid-infrared photothermal conversion efficiency through its thermal effect.

[0029] The two work together: 1) The rectangular structures of the grating structure are distributed throughout the microstructure area. Through its guiding and collimating effects, the light energy is effectively concentrated in the local area where the cross-shaped structure is located, significantly enhancing the light capture ability of the plasmon resonance. 2) The grating structure is mainly responsible for the coupling and modulation of the macroscopic light field, while the cross-shaped structure focuses on the enhancement of the local electromagnetic field and the improvement of the carrier efficiency. The combination of the two can improve the light absorption efficiency and charge separation efficiency in both directions.

[0030] In this application, the tantalum nickel selenium nanosheets are only in contact with the local area of ​​the upper gold layer of the exciton microstructure and grating structure, and there are reserved non-contact areas. The energy band alignment of tantalum nickel selenium and gold mainly occurs at the interface where they are in direct contact, resulting in interface energy band bending, and the interface effect is the main factor. 1. Tantalum nickel selenium is a two-dimensional layered material, and its photoelectric properties are mainly concentrated on the surface; 2. The semi-contact structure of gold and tantalum nickel selenium mainly realizes its main functions through surface local effects: electromagnetic field enhancement, charge accumulation, and thermal diffusion. For example, the local surface plasmon resonance (LSPR) enhancement effect is limited to the nanoscale range near the surface, and the tantalum nickel selenium material in the non-contact area participates in the light absorption and carrier generation process; 3. After the surface absorbs light energy, it will be converted into heat through the surface plasmon effect and diffuse to the non-contact tantalum nickel selenium area.

[0031] The present invention discloses a tantalum nickel selenium mid-infrared detector based on microstructure regulation and its application. The device preparation step first uses ultraviolet lithography technology and electron beam evaporation technology to manufacture four contact electrodes, and then uses electron beam exposure technology and electron beam evaporation technology to fill the designed metal microstructure in the channel to enhance the absorption of light of a specific wavelength. After that, the tantalum nickel selenium nanosheet is dry-transferred to the top of the microstructure, and the boron nitride nanosheet is transferred as a protective layer to isolate the tantalum nickel selenium nanosheet from the air. Finally, the preparation of the tantalum nickel selenium mid-infrared detector is completed by a bonding process. The tantalum nickel selenium mid-infrared detector of the present invention can realize multiple functions such as enhancement of mid-wave infrared light response and self-driven mid-infrared detection through different circuit designs. In addition, the present invention breaks through the bandgap limitation of traditional photoelectric detection, thereby showing obvious advantages in mid-infrared detection. The advantages of the present invention include high stability, self-driven detection, high response rate and fast response. At the same time, the degree of freedom provided by the device structure is conducive to integration and construction of complex logic circuits, and is expected to be applied in smart chips, image processing and optical computing in the future.

[0032] The tantalum-nickel-selenium mid-infrared detector based on microstructure regulation and its application of the present invention have the following beneficial effects: 1. Asymmetric microstructures were prepared on the substrate by electron beam exposure and electron beam evaporation, including plasmon microstructures and grating microstructures. The difference between the two lies in the presence or absence of dipoles to achieve plasmon resonance, which can achieve mid-infrared absorption enhancement and asymmetric temperature distribution in the microstructure area. In addition, the plasmon metasurface introduces a new photoelectric detection mechanism based on hot carrier injection, which realizes ultra-high-speed detection of low-energy photons and greatly improves the response speed.

[0033] 2. The room temperature stable, easy to cleave and narrow bandgap tantalum nickel selenium two-dimensional material grown by chemical vapor deposition is used as the channel photosensitive medium. Its bandgap can basically maintain a direct bandgap of 0.36 eV as the thickness of the material changes. The material is a layered material stacked by weak van der Waals interactions, and the layers are composed of periodic sawtooth wave chains. It is precisely because of this unique atomic structure that while maintaining stability, it is easy to produce relatively regular long strips during mechanical peeling, which is conducive to the integration and design of the device. Tantalum nickel selenium nanosheets are integrated at the microstructure using the transfer platform micro-area positioning method and dry transfer technology. The use of hexagonal boron nitride as a protective layer can further improve the stability of the device.

[0034] 3. The structure of the tantalum nickel selenium mid-infrared detector is relatively simple and the process is mature. Under the regulation of the microstructure, the response rate and response speed of tantalum nickel selenium are greatly improved, and self-driven detection of mid-wave infrared at room temperature is realized. The combination of electromagnetic structure and light response material realizes the improvement of detection performance and the expansion of functions, providing an effective way to regulate the multifunctionality of two-dimensional optoelectronic materials.

[0035] Microstructures, as subwavelength patterned surfaces with strong light interactions, become promising candidates for subsequent iterations of photodetectors. Carefully designed subwavelength nanostructures can achieve local field enhancement and optimal absorption at the desired wavelength, leading to a significant improvement in responsivity. Notably, plasmonic metasurfaces introduce a new photodetection mechanism based on hot carrier injection, achieving ultra-high-speed detection of low-energy photons. To date, plasmon-enhanced multilayer MoS 2 and InSe have been successfully demonstrated in the visible light range. However, some new two-dimensional materials such as Ta 2 NiSe 5 , the high response of plasmon enhancement in the mid-infrared band is still under exploration. Based on the above background research, the present invention innovatively proposes a tantalum nickel selenium mid-infrared detector based on microstructure regulation and encapsulated by hexagonal boron nitride nanosheets, and further studies its preparation method and multifunctional optoelectronic properties.

[0036] The present invention discloses an application of a tantalum nickel selenium mid-infrared detector based on microstructure regulation, which is used for high-performance multifunctional detection of medium-wave infrared. The laser is focused through an optical path, and a control signal is input to enable a mechanical shutter to realize data stream transmission. The tantalum nickel selenium mid-infrared detector based on microstructure regulation is used as a signal receiver to transmit the target data stream, convert the optical signal into an electrical signal, and the read signal is collected by a preamplifier, a phase-locked amplifier and an oscilloscope, and finally decoded on a computer to realize photocurrent collection, and key performance parameters such as response rate, response speed and self-driven detection are evaluated. Example 1

[0037] The thickness of the silicon substrate covered with silicon oxide is 500 μm; the thickness of the tantalum nickel selenide nanosheet is 95 nm, and the thickness of the hexagonal boron nitride nanosheet is 15 nm; the overall size of the four contact electrodes is 100 μm×100 μm, and the overall size of the plasmon microstructure area and the grating structure area are both 30 μm×30 μm; the thickness of the above microstructures and electrodes is 60 nm, the thickness of chromium is 10 nm, and the thickness of gold is 50 nm; the first positive electrode 3, the first negative electrode 4, the second positive electrode 5, and the second negative electrode 6 are connected to different circuits according to different functions for various photoelectric tests. The front view and top view of the tantalum nickel selenium mid-infrared detector are shown in the figure. Figure 1 and Figure 2As shown, contact electrodes and microstructures are prepared on a pre-prepared silicon substrate by electron beam exposure and other processes. Then, tantalum nickel selenium nanosheets are dry-transferred to the top of the microstructure, and boron nitride nanosheets are transferred as a protective layer to isolate the tantalum nickel selenium nanosheets from the air. Figure 3 A schematic diagram showing the size parameters of different microstructure units in the tantalum nickel selenium mid-infrared detector - plasmon microstructure and grating structure, where the dipole length L that generates plasmons 2 is 1.6 μm, width W is 0.1 μm, grating width L 1 The optical absorption rate of the plasmon microstructure at 3-6 μm was simulated and tested. Figure 4 As shown in Figure 2, the good consistency between the experimental results and the simulation results shows the reliability of the microstructure design. At the same time, the electric field intensity magnification and temperature distribution of the plasmon microstructure unit were simulated when the wavelength was 4.6 μm. The results are shown in Figure 2. Figure 5 As shown, it is demonstrated that the plasmon microstructure can effectively amplify the electric field and increase the temperature, providing a theoretical basis for subsequent mid-infrared detection and proving the feasibility of the device design. Example 2

[0038] The thickness of the silicon substrate covered with silicon oxide is 500 μm; the thickness of the tantalum nickel selenium rice sheet is 95 nm, and the thickness of the hexagonal boron nitride nanosheet is 15 nm; the overall size of the four contact electrodes is 100 μm×100 μm, and the overall size of the plasmon microstructure area and the grating microstructure area is 30 μm×30 μm; the thickness of the above microstructures and electrodes is 60 nm (chromium 10 nm / gold 50 nm); the first positive electrode 3, the first negative electrode 4, the second positive electrode 5, and the second negative electrode 6 are connected to different circuits according to different functions for various photoelectric tests. First, the morphology of the device structure was characterized by a microscope and a photoelectric test system was used. By connecting the first positive electrode 3, the first negative electrode 4, the second positive electrode 5, and the second negative electrode 6 respectively, a mid-infrared photocurrent scanning test was performed on the 4.6 um area of ​​the plasmon microstructure and grating microstructure under a bias of 0.1 V. The results are shown as follows Figure 6 As shown in the figure, the difference in color between the two corresponds to the strength of the photocurrent. The comparison shows that the plasmon microstructure is significantly enhanced compared to the grating microstructure, proving the enhancement effect of plasmon on mid-infrared response. Figure 7The photocurrent sizes of the plasmon microstructure and grating microstructure of the tantalum nickel selenide mid-infrared detector at 520 nm, 638 nm, 940 nm, 1064 nm, 1310 nm, 1550 nm and 4.6 um are shown at a bias voltage of 0.1 V. As the wavelength gradually approaches the target mid-infrared band, the photocurrent enhancement effect reaches a maximum, and the enhancement of the light response is more intuitively observed, indicating that the designed plasmon microstructure can effectively enhance the mid-infrared response of the tantalum nickel selenide two-dimensional material. Example 3

[0039] The thickness of the silicon substrate covered with silicon oxide is 500 μm; the thickness of the tantalum nickel selenide rice sheet is 95 nm, and the thickness of the hexagonal boron nitride nanosheet is 15 nm; the overall size of the four contact electrodes is 100 μm×100 μm, and the overall size of the plasmon microstructure area and the grating microstructure area are both 30 μm×30 μm; the thickness of the above microstructures and electrodes is 60 nm (chromium 10 nm / gold 50 nm); the first positive electrode 3, the first negative electrode 4, the second positive electrode 5, and the second negative electrode 6 are connected to different circuits according to different functions for various photoelectric tests. The waveform of the photocurrent of the tantalum nickel selenium mid-infrared detector was read by a phase-locked amplifier and an oscilloscope, and the 4.6 um mid-infrared response time of the plasmon microstructure and grating microstructure under a bias of 0.1 V was extracted from it. Figure 7 As shown in Figures (a) and (b) in Figure 1, the response time of the plasmon microstructure is shortened by nearly an order of magnitude, proving that the hot electrons generated by plasmons can effectively improve the mid-infrared response speed. The response rate of the tantalum nickel selenium mid-infrared detector was then calculated and obtained as follows: Fig. 9 The 4.6 um mid-infrared responsivity of the plasmon microstructure and grating microstructure under a bias of 0.1 V as the incident power changes is shown. As the power changes, the mid-infrared responsivity of the plasmon microstructure is always higher than that of the grating microstructure. The response rate is the core indicator of photoelectric detection, and its improvement can fully demonstrate that the regulation of plasmon microstructure is an important means to improve the photoelectric properties of the material itself. Example 4

[0040] The thickness of the silicon substrate covered with silicon oxide is 500 μm; the thickness of the tantalum nickel selenium rice sheet is 95 nm, and the thickness of the hexagonal boron nitride nanosheet is 15 nm; the overall size of the four contact electrodes is 100 μm×100 μm, and the overall size of the plasmon microstructure area and the grating microstructure area are both 30 μm×30 μm; the thickness of the above microstructures and electrodes is 60 nm (chromium 10 nm / gold 50 nm); the first positive electrode 3, the first negative electrode 4, the second positive electrode 5, and the second negative electrode 6 are connected to different circuits according to different functions for various photoelectric tests. The overall microstructure was characterized by a 4.6μm photocurrent scan under a 0 V bias by connecting the first positive electrode 3 and the second negative electrode 6, and the results are shown as follows: Fig.10 As shown, an obvious asymmetric distribution of photocurrent can be observed. In order to compare its size more intuitively, the photocurrent distribution at the middle section is also shown. The directions of the photocurrents on the left and right sides are opposite, and the photocurrent generated by the plasmon microstructure is significantly larger than that of the grating structure. This not only realizes self-driven mid-infrared detection, but also illustrates the enhancement effect of the plasmon microstructure, proving that the asymmetric microstructure can effectively expand the mid-infrared detection performance.

[0041] 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. A tantalum-nickel-selenium mid-infrared detector based on microstructure regulation, characterized in that: A silicon dioxide layer is arranged on an intrinsic high-resistance silicon substrate, and a plasmon microstructure is arranged on the silicon dioxide layer, which is rectangular as a whole. The plasmon microstructure includes two cross-shaped plasmon microstructures, which are arranged in an interdigitated manner with a spacing, and each cross-shaped plasmon microstructure is connected to a first positive electrode and a first negative electrode respectively; the cross-shaped plasmon metal microstructure includes a plurality of cross-shaped resonance structure units, which are evenly distributed on the interdigitated structures; a grating structure is also arranged on the silicon dioxide layer, which is rectangular as a whole, and the grating structure is arranged with a spacing from the plasmon microstructure, and the grating structure includes two grating microstructures, which are arranged in an interdigitated manner with a spacing, and each grating microstructure is connected to a second positive electrode and a second negative electrode respectively; a tantalum-nickel-selenium nanosheet is covered on the plasmon microstructure and the grating structure, and a hexagonal boron nitride nanosheet protective layer is covered on the tantalum-nickel-selenium nanosheet; The plasmon microstructure and grating structure are composite metal structures, with gold as the upper metal. By aligning the energy bands of tantalum, nickel and selenium and gold in tantalum-nickel-selenium nanosheets, the local resonance enhancement effect produced by the synergistic plasmon microstructure and the enhanced incident light coupling by the grating structure, the detector's mid-infrared absorption is enhanced, and the mid-infrared response at room temperature is enhanced, thus realizing mid-infrared self-driven detection at room temperature.

2. The tantalum-nickel-selenium mid-infrared detector based on microstructure regulation according to claim 1, characterized in that: The lower metal of the plasmonic microstructure is chromium with a thickness of 10 nm, the upper metal is gold with a thickness of 50 nm, and the overall size is 30 μm × 30 μm; The cross-shaped plasmon microstructure includes 6 cross-shaped plasmon columns, which are arranged in a finger-like form with a width of 0.2 μm and a spacing of 0.9µm. The cross-shaped resonance structure units are evenly distributed on each cross-shaped plasmon column. The dipole length of the plasmon of each cross-shaped resonance structure unit is 1.6 μm and the width is 0.1 μm. The structural period of the cross-shaped resonance structure unit is 2.5 μm.

3. The tantalum-nickel-selenium mid-infrared detector based on microstructure regulation as claimed in claim 1, characterized in that: The grating structure is a chrome-gold composite structure. The lower metal is chrome, which serves as an adhesion layer with a thickness of 10 nm, and the upper metal is gold with a thickness of 50 nm. The overall size is 30 μm×30 μm. The grating microstructure includes 6 grating microcolumns, which are arranged in the form of fingers. Each grating microcolumn is rectangular, with a width of 0.2 μm, and a period of each grating microcolumn is 2.5 μm.

4. The tantalum-nickel-selenium mid-infrared detector based on microstructure regulation as claimed in claim 1, characterized in that: The resistivity of the intrinsic high-resistance silicon substrate is >10000 Ω·cm and the thickness is 500 μm; The thickness of the silicon dioxide layer is 300 nm; The thickness of the tantalum nickel selenium nanosheet is 95 nm; The thickness of the hexagonal boron nitride nanosheet is 15 nm.

5. The tantalum-nickel-selenium mid-infrared detector based on microstructure regulation as claimed in claim 1, characterized in that: The first positive electrode, the first negative electrode, the second positive electrode and the second negative electrode are chromium-gold composite electrodes, the lower metal is chromium, which serves as an adhesion layer with a thickness of 10 nm, the upper metal is gold with a thickness of 50 nm, and the overall size of the four contact electrodes is 100 μm×100 μm.

6. Application of the tantalum-nickel-selenium mid-infrared detector based on microstructure regulation according to any one of claims 1 to 5, characterized in that: It is used in signal receivers to transmit target data streams, convert optical signals into electrical signals, and the signals are collected and read by preamplifiers, phase-locked amplifiers and oscilloscopes. Finally, they are decoded on the computer side to realize photocurrent collection, and key performance parameters such as response rate, response speed and self-driven detection are evaluated.

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