Terahertz detector and preparation method of terahertz detector

Abstract

The application discloses a terahertz detector and a preparation method of the terahertz detector. The terahertz detector comprises a substrate, a channel material layer and an electrode. The channel material layer is arranged on the substrate, and a channel material in the channel material layer comprises a transition metal chalcogenide subjected to element intercalation; and the electrode is in contact with the channel material layer. The terahertz detector and the preparation method of the terahertz detector can modify the energy band structure, physical properties and carrier transport characteristics of the transition metal chalcogenide by element intercalation, and can realize high-performance terahertz detection when the transition metal chalcogenide is applied to the terahertz detector, which is a simple and easy way.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor devices, and in particular to a terahertz detector and a method for preparing the terahertz detector. Background Art

[0002] Two-dimensional transition metal chalcogenides (such as TaS2, TaSe2, NbSe2, etc.) usually have rich phase structures such as 1T, 2H and 3R phases. They also contain novel physical properties such as superconductivity, charge density waves, metal-insulator transition and unique band structures. They are one of the research hotspots in condensed matter physics.

[0003] Terahertz waves are located between microwave electronics and infrared photonics (0.1-10THz), and have unique advantages such as high bandwidth, good penetration, high resolution and security. They have broad application prospects in space communications, astronomical detection, security imaging and national defense. High-performance terahertz detectors are the key to the application of terahertz technology.

[0004] Traditional commercial terahertz detectors struggle to strike a good balance between response speed, sensitivity, and operating temperature. Furthermore, existing technologies often improve terahertz detection sensitivity through heterojunction construction or by operating the device at low temperatures, which inevitably increases device fabrication complexity, power consumption, and complicates device integration. Device response time is closely related to intrinsic carrier relaxation and channel length. Reducing the channel length shortens carrier transit time, improving response speed, but this significantly increases the precision requirements of the corresponding process equipment.

[0005] In recent years, topological semimetals have demonstrated significant advantages in terahertz detection due to their intrinsic topological band structure, linear band dispersion, chiral anomalies, nonlinear optical response, and nonlinear Hall effect. However, the response mechanisms of terahertz detectors based on novel topological semimetals and other material systems are largely unclear, and their unique physical properties are difficult to correlate with terahertz response performance. Therefore, the exploration of novel material systems, device structures, and corresponding new detection mechanisms is urgently needed.

[0006] Element intercalation is an effective way to regulate the physical properties and band structure of two-dimensional transition metal chalcogenides, and is expected to achieve a significant improvement in terahertz performance.

[0007] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the Invention

[0008] The object of the present invention is to provide a terahertz detector and a method for preparing the terahertz detector, which can achieve high-performance terahertz detection.

[0009] To achieve the above objectives, an embodiment of the present invention provides a terahertz detector comprising: a substrate, a channel material layer, and an electrode. The channel material layer is disposed on the substrate, wherein the channel material in the channel material layer comprises a transition metal chalcogenide undergoing element intercalation; and the electrode is in contact with the channel material layer.

[0010] In one or more embodiments of the present invention, the chemical formula of the transition metal chalcogenide compound for element intercalation is P i MX2, wherein P is an intercalation element, M is a transition metal element, and X is a chalcogen element.

[0011] In one or more embodiments of the present invention, the intercalation element is selected from metal or non-metal elements; the transition metal element is selected from Nb or Ta; and the chalcogenide element is selected from S or Se.

[0012] In one or more embodiments of the present invention, the intercalation element is selected from: Ni, Co, Mn, V, Cr, Ge or In.

[0013] In one or more embodiments of the present invention, the terahertz detector further includes an antenna structure, wherein the antenna structure is formed on the substrate and is in contact with the channel material layer and the electrode.

[0014] Another embodiment of the present invention provides a method for preparing a terahertz detector, comprising:

[0015] providing a substrate;

[0016] Providing a channel material, wherein the channel material includes a transition metal chalcogenide compound undergoing element intercalation, and transferring the channel material to the surface of the substrate to form a channel material layer;

[0017] An electrode is formed on the substrate, wherein the electrode is in contact with the channel material layer.

[0018] In one or more embodiments of the present invention, a metal mark is formed on the substrate; after the step of transferring the channel material to the surface of the substrate to form a channel material layer, the position of the channel material layer and its corresponding metal mark is recorded.

[0019] In one or more embodiments of the present invention, the step of forming an electrode on the substrate, wherein the electrode contacts the channel material layer, includes: forming an electrode on the substrate, wherein the electrode connects the channel material layer and the metal mark.

[0020] In one or more embodiments of the present invention, the chemical formula of the transition metal chalcogenide compound for element intercalation is P i MX2, wherein P is an intercalation element, M is a transition metal element, and X is a chalcogen element; the intercalation element is selected from metal or non-metal elements, and the intercalation element is selected from: Ni, Co, Mn, V, Cr, Ge or In; the transition metal element is selected from: Nb or Ta; the chalcogen element is selected from: S or Se.

[0021] In one or more embodiments of the present invention, the transition metal chalcogenide-P for element intercalation is synthesized by chemical vapor transport method. i MX2.

[0022] In one or more embodiments of the present invention, the step of providing a channel material and transferring the channel material to the surface of the substrate to form a channel material layer comprises: preparing the channel material: in a vacuum environment, inversely growing the intercalation element P, the transition metal element M and the chalcogenide element X at 850-900°C in a stoichiometric ratio for three days to obtain polycrystalline particles; forward growing the polycrystalline particles at 950-830°C for seven days, and then lowering the temperature to ambient temperature to obtain P i MX2 crystal; P i MX2 crystal is cleaved into P by mechanical exfoliation i MX2 nanosheets are transferred to the substrate surface.

[0023] In one or more embodiments of the present invention, the method for preparing the terahertz detector further includes the step of forming an antenna structure on the substrate, wherein the antenna structure is in contact with the channel material layer, and the electrode is connected to the antenna structure.

[0024] Compared with the prior art, the terahertz detector and the method for preparing the terahertz detector according to the embodiments of the present invention modify the energy band structure, physical properties and carrier transport characteristics of the transition metal chalcogenide by element intercalation, and apply it to the terahertz detector, thereby achieving high-performance terahertz detection, which is a simple and easy way.

[0025] According to the terahertz detector and the method for preparing the terahertz detector according to the embodiments of the present invention, due to the unique properties brought about by element intercalation of transition metal chalcogenides, the transition metal chalcogenides after element intercalation are applied to the terahertz detector, so that the responsiveness and response speed of the terahertz detector are greatly improved at the same time.

[0026] According to the terahertz detector and the method for preparing the terahertz detector according to the embodiments of the present invention, by comparing the intrinsic properties of the material before and after element intercalation with the actual detection performance, the corresponding terahertz detection mechanism in the new material system can be further clarified. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 3 is a schematic structural diagram of a terahertz detector according to one embodiment of the present invention.

[0028] Figure 2 is a cross-sectional view of a terahertz detector according to one embodiment of the present invention.

[0029] Figure 3a This is a portion of an electronic layout used for preparing a terahertz detector according to one embodiment of the present invention;

[0030] Figure 3b It is a light microscopy image of a material positioning mark for drawing a device structure in a terahertz detector prepared according to one embodiment of the present invention;

[0031] Figure 3c is based on Figure 3b Light microscopy image of the positioning marks showing the prepared antenna structure and electrodes.

[0032] Figure 4a is the XRD pattern of NbS2;

[0033] Figure 4b 1 is an XRD pattern of NbS2 with Ni element intercalation according to Example 1 of the present invention.

[0034] Figure 5a This is the EDS mapping of NbS2 with Ni element intercalation according to Example 1 of the present invention.

[0035] Figure 5b 1 is an energy spectrum diagram of NbS2 with Ni element intercalation according to Example 1 of the present invention.

[0036] Figure 6a is the response current diagram of NbS2;

[0037] Figure 6b This is a graph of the NbS2 response current of the Ni element intercalation according to Example 1 of the present invention.

[0038] Figure 7a is the response time graph of NbS2;

[0039] Figure 7b 3 is a time diagram of the NbS2 response of the Ni element intercalation according to Example 1 of the present invention. DETAILED DESCRIPTION

[0040] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0041] Unless expressly stated otherwise, throughout the specification and claims, the term "comprise" or variations such as "include" or "comprising", etc., will be understood to include the stated elements or components but not to exclude other elements or other components.

[0042] like Figure 1 and Figure 2 As shown, a terahertz detector according to an embodiment of the present invention includes a substrate 10, a channel material layer 20, an antenna structure 30 and an electrode 40. The channel material layer 20 is provided on the substrate 10, and the channel material in the channel material layer 20 includes a transition metal chalcogenide compound undergoing element intercalation. The antenna structure 30 is formed on the substrate 10 and contacts the channel material layer 20 and the electrode 40. The electrode 40 contacts the channel material layer 20 through the antenna structure 30. The chemical formula of the transition metal chalcogenide compound undergoing element intercalation is P i MX2, P is an intercalation element, M is a transition metal element, and X is a chalcogen element.

[0043] Exemplarily, the intercalation element is selected from a metal or non-metal element. The transition metal element is selected from Nb or Ta. The chalcogenide element is selected from S or Se. Preferably, the intercalation element is selected from Ni, Co, Mn, V, Cr, Ge, or In.

[0044] In one embodiment of the present invention, the transition metal chalcogenide compound-P for element intercalation can be synthesized by chemical vapor transport method. i Specifically, the intercalation element P, transition metal element M, and chalcogen element X in a stoichiometric ratio are placed in a quartz tube, and a transport agent is added to the quartz tube; the quartz tube is evacuated to a high vacuum (2×10 -5 Pa), use an oxygen / hydrogen welding gun to seal the quartz tube; put the quartz tube into a dual-temperature zone tubular furnace, and perform reverse growth at 850-900°C for three days to obtain polycrystalline particles; then perform forward growth at 950-830°C for seven days; when the temperature of the quartz tube naturally drops to ambient temperature, the tubular furnace is no longer heated, and it is allowed to cool naturally, and high-quality PiMX2 crystals can be obtained, the color of which shows a distinct metallic luster. Among them, the chemical vapor transport method usually uses a tubular furnace to grow crystals. The tubular furnace has two temperature zones. Usually, the high-temperature end is the raw material end, and the low-temperature end is the growth end. Finally, the crystal grows at the low-temperature end, which is called forward growth. Inverse growth refers to placing the raw material in a low-temperature section. As a result, a large number of polycrystalline particles will be obtained at the low-temperature raw material end, and only a small amount of product will exist at the high-temperature growth end.

[0045] The present invention also provides a method for preparing a terahertz detector, comprising: providing a substrate with a metal mark formed on the substrate; providing a channel material, the channel material comprising a transition metal sulfide compound undergoing element intercalation, transferring the channel material to the surface of the substrate to form a channel material layer and recording the position of the channel material layer and its corresponding metal mark; forming an antenna structure on the substrate, the antenna structure being in contact with the channel material layer; forming an electrode on the substrate, the electrode being connected to the antenna structure and the metal mark and being in contact with the channel material layer through the antenna structure. The chemical formula of the transition metal sulfide compound undergoing element intercalation is P i MX2, P is an intercalation element, M is a transition metal element, and X is a chalcogen element.

[0046] Exemplarily, the intercalation element is selected from metal or non-metal elements; preferably, the intercalation element is selected from Ni, Co, Mn, V, Cr, Ge, or In. The transition metal element is selected from Nb or Ta. The chalcogen element is selected from S or Se.

[0047] Exemplary, reference Figure 3a As shown, the step of providing a substrate includes:

[0048] A four-inch silicon wafer was cleaned with acetone, isopropyl alcohol, and deionized water. Metal marks were then prepared on the wafer through UV lithography, coating, and other processes. The metal marks facilitated alignment during subsequent electron beam lithography of antenna structures and electrodes. Finally, the wafer was cut into 1.5*1.5 cm pieces for subsequent device fabrication.

[0049] Exemplary, reference Figure 3b As shown, the steps of providing a channel material and transferring the channel material to the surface of the substrate to form a channel material layer include:

[0050] Preparation of channel material: Synthesize the transition metal chalcogenide-P for element intercalation by chemical vapor transport method i Specifically, the intercalation element P, transition metal element M, and chalcogen element X in a stoichiometric ratio are placed in a quartz tube, and a transport agent is added to the quartz tube; the quartz tube is evacuated to a high vacuum (2×10 -5 Pa), the quartz tube is sealed with an oxygen / hydrogen torch; the quartz tube is placed in a dual-temperature zone tube furnace and grown at 850-900 ° C for three days in reverse growth to obtain polycrystalline particles, and then grown at 950-830 ° C for seven days in the forward direction; when the temperature of the quartz tube naturally drops to ambient temperature, the tube furnace is no longer heated and allowed to cool naturally to obtain high-quality P iMX2 crystals exhibit a distinct metallic luster. Chemical vapor transport (CVT) methods typically utilize a tube furnace to grow crystals. Tube furnaces have two temperature zones: the high-temperature end, which serves as the feedstock, and the low-temperature end, which serves as the growth zone. Crystals ultimately grow at the low-temperature end, a process known as forward growth. Inverse temperature growth involves subjecting the feedstock to a low temperature, resulting in a large number of polycrystalline particles at the low-temperature feedstock end and only a small amount of product at the high-temperature growth end.

[0051] P i MX2 crystal is cleaved into P by mechanical exfoliation i MX2 nanosheets are transferred to the substrate surface coated with metal markers.

[0052] Use an optical microscope to take photos and record the placed P i The location of MX2 nanosheets (including P i The position of MX2 nanosheets and their corresponding metal markers is used to draw electronic layouts. i The position of MX2 nanosheets is random, so it is necessary to take a photo to record P i The location of the MX2 nanosheet and the metal markings around it are used to identify the P in the electronic layout. i MX2 nanosheets are positioned and the device structure is drawn at the specified location.

[0053] For example, Figure 3c As shown, the steps of forming an antenna structure and an electrode on a substrate include:

[0054] The antenna structure and electrodes (the electrodes connect the antenna structure to the metal marker A (refer to Figure 1 The metal marking facilitates subsequent testing and lead packaging using a probe station. Finally, a complete terahertz detector is fabricated using mature semiconductor packaging and lead packaging technologies.

[0055] In order to conduct performance testing of the terahertz detector of the present invention, the above-mentioned chemical vapor transport method can be used to synthesize a transition metal sulfide compound that has not undergone element intercalation, and the above-mentioned terahertz detector preparation method can be used to prepare the transition metal sulfide compound that has not undergone element intercalation into a terahertz detector, wherein all parameter conditions (thickness, size, etc.) are consistent with the above-mentioned embodiment.

[0056] A self-built terahertz test system was used to test the performance of terahertz detectors fabricated using element-intercalated transition metal chalcogenides as channel materials, as well as terahertz detectors fabricated using non-intercalated transition metal chalcogenides as channel materials. Under identical test conditions, a comparison of the response photocurrent and response time of the two devices revealed that the application of element-intercalated transition metal chalcogenides in terahertz detectors significantly improved both the responsivity and response speed. The self-built terahertz test system utilizes an E8257D microwave signal source equipped with a VDI frequency multiplier, enabling output in the 0.02-0.3 THz frequency range, enabling testing of the detector's terahertz response performance. The self-built terahertz test system also features an SR770 noise analyzer for testing and analyzing the detector's noise level.

[0057] Example 1 (Ni intercalated NbS2):

[0058] Niobium disulfide (NbS2), a typical layered transition metal chalcogenide, has attracted widespread attention from researchers due to its superconductivity and unique optical, electrical, and magnetic properties. Recent research results have shown that NbS2 also exhibits charge density wave properties, making it an ideal material system for exploring the interplay between superconductivity and quantum order such as charge density waves.

[0059] By intercalating niobium disulfide (M x NbS2) to achieve unique band structures, novel physical properties, and physical effects. For example, Co intercalation into 2H-NbS2 can break spatial inversion symmetry, resulting in linear band dispersion near the Fermi level, antiferromagnetic properties, and an anomalous Hall effect derived from the Berry curvature. In intercalation can also bring about strong spin-orbit coupling, transforming the band structure of ordinary metals into the unique band structure of Weyl semimetals. The unique band structures and novel physical properties brought about by such elemental intercalation have significant potential for improving terahertz detection performance and exploring new detection mechanisms.

[0060] The following takes niobium disulfide (NbS2) and niobium disulfide (NbS2) with element intercalation as channel materials for terahertz detectors as an example to elaborate on the technical solution of the present invention in detail, and demonstrates through specific experimental data that the terahertz detector using niobium disulfide (NbS2) with element intercalation as the channel material has greatly improved responsivity and response speed.

[0061] Step 1: Preparation of niobium disulfide (NbS2) with element intercalation:

[0062] Chemical vapor transport (CVT) was used to synthesize high-quality M xNbS2 crystals. A total of 0.5g of stoichiometrically intercalated element M, Nb, and S powders (Alfaaesar, 99.99%) and iodine (as a transport agent, ~3mg / ml) were placed in a quartz tube (20mm outer diameter, 16mm inner diameter, 150mm length). The masses of the components will vary depending on the intercalated element M. Here, NiNb3S6 is used as an example. The stoichiometric ratio of the three elements is 1:3:6, and the relative atomic mass ratio is 59:93:32. The calculated mass ratios of the three elements are 11.1:52.7:36.2, resulting in 55.5mg of Ni, 63.5mg of Nb2, and 181mg of S. Iodine was added at a concentration of ~3mg / ml, depending on the volume of the quartz tube.

[0063] Use a molecular pump to evacuate to high vacuum (2×10 -5 Pa), and then the quartz tube is sealed using an oxygen / hydrogen torch. Further, the quartz tube is placed in a dual-temperature tube furnace and grown at 850-900 ° C for three days in reverse growth to obtain polycrystalline particles, and then grown at 950-830 ° C for seven days in the forward direction. When the temperature of the quartz tube naturally drops to ambient temperature, high-quality M x NbS2 crystal, its color shows obvious metallic luster.

[0064] Using the CVT method, a specific ratio of 1:3:6 MNb3S6 crystals can be synthesized according to the stoichiometric ratio of the raw materials, where the M atomic layers are intercalated. This intercalation disrupts the inherent symmetry of single niobium disulfide, achieving symmetry breaking. Furthermore, the intercalation of elements such as Ni, Co, and Mn may introduce novel properties such as magnetism and topological states. These changes in properties can be explored through transport measurements and band structure characterization.

[0065] M for CVT preparation x The basic characterization of NbS2 was carried out by SEM, XRD, STEM, EDS and XPS to confirm whether the intercalation was successful, the crystal structure after intercalation and the element ratio of the material. Angle Resolved Photo Electron Spectroscopy (ARPES) was used to characterize M x The band structure of NbS2 was observed, and the magnetic properties of the macroscopic crystal bulk were measured by a vibrating sample magnetometer (VSM) and a comprehensive physical property measurement system (PPMS) to explore the material's transport properties (high mobility, magnetoresistance, etc.).

[0066] Step 2: Preparation of terahertz detector based on Ni intercalated niobium disulfide (NbS2):

[0067] First, a four-inch silicon wafer is cleaned with acetone, isopropyl alcohol, and deionized water. Metal marks are then prepared on the wafer through UV lithography, coating, and other processes to facilitate alignment during subsequent electron beam lithography of the antenna structure and electrodes. Finally, the four-inch wafer is cut into 1.5*1.5 cm pieces for subsequent device preparation.

[0068] Secondly, the element-intercalated niobium disulfide crystals were cleaved into nanosheets by mechanical exfoliation and transferred to Si / SiO2 (625μm / 300nm) substrates coated with metal tags.

[0069] Then, an optical microscope is used to take photos to record the position of the selected nanosheets for drawing the electronic layout. Since the position of the nanosheets transferred by mechanical exfoliation onto the Si / SiO2 substrate is random, it is necessary to take photos to record the position of the nanosheets and the metal marks around them so that the nanosheets can be positioned in the electronic layout and the device structure (such as Figure 3a 、 Figure 3b 、 Figure 3c shown).

[0070] Next, the antenna structure and electrodes are prepared through techniques such as electron beam lithography, electron beam evaporation and metal stripping (the electrodes connect the antenna to the metal markers, which facilitate subsequent testing and lead packaging using a probe station).

[0071] Finally, the device is packaged and tested, and a complete terahertz detector is prepared using mature semiconductor packaging and lead technology.

[0072] In order to conduct performance testing of the terahertz detector of the present invention, the above-mentioned chemical vapor transport method can be used to synthesize niobium disulfide (NbS2) without Ni element intercalation, and the above-mentioned terahertz detector preparation method can be used to prepare niobium disulfide (NbS2) without Ni element intercalation into a terahertz detector, wherein all parameter conditions (thickness, size, etc.) are consistent with the above-mentioned embodiment to eliminate the influence of material size and thickness on response performance.

[0073] Figure 4a This is the XRD pattern of niobium disulfide (NbS2) without Ni element intercalation provided by the present invention; Figure 4b This is the XRD spectrum of niobium disulfide (NbS2) with Ni element intercalation provided by the present invention. Figure 5a The EDS mapping of Niobium disulfide (NbS2) with Ni intercalation provided by the present invention; Figure 5b This is the energy spectrum of niobium disulfide (NbS2) with Ni element intercalation provided by the present invention. Figure 6a This is a response current diagram of niobium disulfide (NbS2) without Ni element intercalation provided by the present invention; Figure 6bThis is a response current diagram of niobium disulfide (NbS2) with Ni element intercalation provided by the present invention. Figure 7a This is a response time diagram of niobium disulfide (NbS2) without Ni element intercalation provided by the present invention; Figure 7b This is a response time diagram of niobium disulfide (NbS2) with Ni element intercalation provided by the present invention.

[0074] pass Figure 4a 、 Figure 4b 、 Figure 5a and Figure 5b The successful intercalation of Ni element can be demonstrated. Figure 6a 、 Figure 6b and Figure 7a 、 Figure 7b It can be seen intuitively that the response current and response speed of niobium disulfide (NbS2) with Ni element intercalation are greatly improved, indicating that Ni element intercalation is an effective way to improve the terahertz detection performance of niobium disulfide devices.

[0075] This study uses niobium disulfide (NbS) before and after Ni intercalation for terahertz detection. The goal is to exploit the post-intercalation characteristics of NbS, including band structure transitions, antiferromagnetism, and the anomalous Hall effect, to achieve high-performance THz detection. The study also seeks to clarify the relationship between these physical properties and THz response.

[0076] Example 2 (Ni intercalated TaS2):

[0077] Step 1: Preparation of TaS2 with element intercalation:

[0078] Chemical vapor transport (CVT) was used to synthesize high-quality M x TaS2 crystal.

[0079] M for CVT preparation x TaS2 was subjected to basic characterization such as SEM, XRD, STEM, EDS and XPS to confirm whether the intercalation was successful, the crystal structure after intercalation and the element ratio of the material. Angle Resolved Photo Electron Spectroscopy (ARPES) was used to characterize M x The band structure of TaS2 was observed, and the magnetic properties of the macroscopic crystal block were measured by a vibrating sample magnetometer (VSM) and a comprehensive physical property measurement system (PPMS) to explore the material's transport properties (high mobility, magnetoresistance, etc.).

[0080] Step 2: Preparation of terahertz detector based on Ni-intercalated TaS2:

[0081] First, a four-inch silicon wafer is cleaned with acetone, isopropyl alcohol, and deionized water. Metal marks are then prepared on the wafer through UV lithography, coating, and other processes to facilitate alignment during subsequent electron beam lithography of the antenna structure and electrodes. Finally, the four-inch wafer is cut into 1.5*1.5 cm pieces for subsequent device preparation.

[0082] Secondly, the element-intercalated TaS2 crystals were cleaved into nanosheets by mechanical exfoliation and transferred to Si / SiO2 (625μm / 300nm) substrates coated with metal tags.

[0083] An optical microscope is then used to photograph the locations of the selected nanosheets for use in drawing the electronic layout. Because the positions of the nanosheets transferred onto the Si / SiO2 substrate by mechanical exfoliation are random, it is necessary to photograph the nanosheet positions and the surrounding metal markers to locate the nanosheets in the electronic layout and draw the device structure at the designated locations.

[0084] Next, the antenna structure and electrodes are prepared through techniques such as electron beam lithography, electron beam evaporation and metal stripping (the electrodes connect the antenna to the metal markers, which facilitate subsequent testing and lead packaging using a probe station).

[0085] Finally, the device is packaged and tested, and a complete terahertz detector is prepared using mature semiconductor packaging and lead technology.

[0086] In order to conduct performance testing of the terahertz detector of the present invention, the above-mentioned chemical vapor transport method can be used to synthesize TaS2 without Ni element intercalation, and the above-mentioned terahertz detector preparation method can be used to prepare TaS2 without Ni element intercalation into a terahertz detector, wherein all parameter conditions (thickness, size, etc.) are consistent with the above-mentioned embodiment to eliminate the influence of material size and thickness on response performance.

[0087] The above-mentioned terahertz detector was tested, and the experiment showed that the response current and response speed of TaS2 with Ni element intercalation were greatly improved, indicating that Ni element intercalation is an effective way to improve the terahertz detection performance of TaS2 devices.

[0088] Example 3 (Ni intercalated TaSe2):

[0089] Step 1: Preparation of TaSe2 with element intercalation:

[0090] Chemical vapor transport (CVT) was used to synthesize high-quality M x TaSe2 crystal.

[0091] M for CVT preparation xTaSe2 was subjected to basic characterization such as SEM, XRD, STEM, EDS and XPS to confirm whether the intercalation was successful, the crystal structure after intercalation and the element ratio of the material. Angle Resolved Photo Electron Spectroscopy (ARPES) was used to characterize M x The band structure of TaSe2 was observed, and the magnetic properties of the macroscopic crystal block were measured by a vibrating sample magnetometer (VSM) and a comprehensive physical property measurement system (PPMS) to explore the material's transport properties (high mobility, magnetoresistance, etc.).

[0092] Step 2: Preparation of terahertz detector based on Ni-intercalated TaSe2:

[0093] First, a four-inch silicon wafer is cleaned with acetone, isopropyl alcohol, and deionized water. Metal marks are then prepared on the wafer through UV lithography, coating, and other processes to facilitate alignment during subsequent electron beam lithography of the antenna structure and electrodes. Finally, the four-inch wafer is cut into 1.5*1.5 cm pieces for subsequent device preparation.

[0094] Secondly, the element-intercalated TaSe2 crystals were cleaved into nanosheets by mechanical exfoliation and transferred to Si / SiO2 (625μm / 300nm) substrates coated with metal tags.

[0095] An optical microscope is then used to photograph the locations of the selected nanosheets for use in drawing the electronic layout. Because the positions of the nanosheets transferred onto the Si / SiO2 substrate by mechanical exfoliation are random, it is necessary to photograph the nanosheet positions and the surrounding metal markers to locate the nanosheets in the electronic layout and draw the device structure at the designated locations.

[0096] Next, the antenna structure and electrodes are prepared through techniques such as electron beam lithography, electron beam evaporation and metal stripping (the electrodes connect the antenna to the metal markers, which facilitate subsequent testing and lead packaging using a probe station).

[0097] Finally, the device is packaged and tested, and a complete terahertz detector is prepared using mature semiconductor packaging and lead technology.

[0098] In order to conduct performance testing of the terahertz detector of the present invention, the above-mentioned chemical vapor transport method can be used to synthesize TaSe2 without Ni element intercalation, and the above-mentioned terahertz detector preparation method can be used to prepare TaSe2 without Ni element intercalation into a terahertz detector, wherein all parameter conditions (thickness, size, etc.) are consistent with the above-mentioned embodiment to eliminate the influence of material size and thickness on response performance.

[0099] The above-mentioned terahertz detector was tested, and the experiment showed that the response current and response speed of TaSe2 with Ni element intercalation were greatly improved, indicating that Ni element intercalation is an effective way to improve the terahertz detection performance of TaSe2 devices.

[0100] Example 4 (Ni intercalated NbSe2):

[0101] Step 1: Preparation of NbSe2 for element intercalation:

[0102] Chemical vapor transport (CVT) was used to synthesize high-quality M x NbSe2 crystal.

[0103] M for CVT preparation x The basic characterization of NbSe2 was carried out by SEM, XRD, STEM, EDS and XPS to confirm whether the intercalation was successful, the crystal structure after intercalation and the element ratio of the material. Angle Resolved Photo Electron Spectroscopy (ARPES) was used to characterize M x The band structure of NbSe2 was observed, and the magnetic properties of the macroscopic crystal bulk were measured by a vibrating sample magnetometer (VSM) and a comprehensive physical property measurement system (PPMS) to explore the material's transport properties (high mobility, magnetoresistance, etc.).

[0104] Step 2: Preparation of terahertz detector based on Ni-intercalated NbSe2:

[0105] First, a four-inch silicon wafer is cleaned with acetone, isopropyl alcohol, and deionized water. Metal marks are then prepared on the wafer through UV lithography, coating, and other processes to facilitate alignment during subsequent electron beam lithography of the antenna structure and electrodes. Finally, the four-inch wafer is cut into 1.5*1.5 cm pieces for subsequent device preparation.

[0106] Secondly, the element-intercalated NbSe2 crystals were cleaved into nanosheets by mechanical exfoliation and transferred to Si / SiO2 (625μm / 300nm) substrates coated with metal tags.

[0107] An optical microscope is then used to photograph the locations of the selected nanosheets for use in drawing the electronic layout. Because the positions of the nanosheets transferred onto the Si / SiO2 substrate by mechanical exfoliation are random, it is necessary to photograph the nanosheet positions and the surrounding metal markers to locate the nanosheets in the electronic layout and draw the device structure at the designated locations.

[0108] Next, the antenna structure and electrodes are prepared through techniques such as electron beam lithography, electron beam evaporation and metal stripping (the electrodes connect the antenna to the metal markers, which facilitate subsequent testing and lead packaging using a probe station).

[0109] Finally, the device is packaged and tested, and a complete terahertz detector is prepared using mature semiconductor packaging and lead technology.

[0110] In order to conduct performance testing of the terahertz detector of the present invention, the above-mentioned chemical vapor transport method can be used to synthesize NbSe2 without Ni element intercalation, and the above-mentioned terahertz detector preparation method can be used to prepare NbSe2 without Ni element intercalation into a terahertz detector, wherein all parameter conditions (thickness, size, etc.) are consistent with the above-mentioned embodiment to eliminate the influence of material size and thickness on response performance.

[0111] The above-mentioned terahertz detector was tested, and the experiment showed that the response current and response speed of NbSe2 with Ni element intercalation were greatly improved, indicating that Ni element intercalation is an effective way to improve the terahertz detection performance of NbSe2 devices.

[0112] Examples 1-4 illustrate that Ni element intercalation is an effective way to improve the terahertz detection performance of niobium disulfide devices, and this approach is also applicable to other transition metal disulfides (such as TaS2, TaSe2, NbSe2, etc.).

[0113] Example 5 (Co intercalated NbS2):

[0114] Step 1: Preparation of NbS2 for element intercalation:

[0115] Chemical vapor transport (CVT) was used to synthesize high-quality M x NbS2 crystal.

[0116] M for CVT preparation xThe basic characterization of NbS2 such as SEM, XRD, STEM, EDS and XPS was carried out to confirm whether the intercalation was successful, the crystal structure after intercalation and the element ratio of the material. Angle Resolved Photo Electron Spectroscopy (ARPES) was used to characterize M x The band structure of NbS2 was observed, and the magnetic properties of the macroscopic crystal bulk were measured by a vibrating sample magnetometer (VSM) and a comprehensive physical property measurement system (PPMS) to explore the material's transport properties (high mobility, magnetoresistance, etc.).

[0117] Step 2: Preparation of terahertz detector based on Co-intercalated NbS2:

[0118] First, a four-inch silicon wafer is cleaned with acetone, isopropyl alcohol, and deionized water. Metal marks are then prepared on the wafer through UV lithography, coating, and other processes to facilitate alignment during subsequent electron beam lithography of the antenna structure and electrodes. Finally, the four-inch wafer is cut into 1.5*1.5 cm pieces for subsequent device preparation.

[0119] Secondly, the Co-intercalated NbS2 crystals were cleaved into nanosheets by mechanical exfoliation and transferred to Si / SiO2 (625μm / 300nm) substrates coated with metal markers.

[0120] An optical microscope is then used to photograph the locations of the selected nanosheets for use in drawing the electronic layout. Because the positions of the nanosheets transferred onto the Si / SiO2 substrate by mechanical exfoliation are random, it is necessary to photograph the nanosheet positions and the surrounding metal markers to locate the nanosheets in the electronic layout and draw the device structure at the designated locations.

[0121] Next, the antenna structure and electrodes are prepared through techniques such as electron beam lithography, electron beam evaporation and metal stripping (the electrodes connect the antenna to the metal markers, which facilitate subsequent testing and lead packaging using a probe station).

[0122] Finally, the device is packaged and tested, and a complete terahertz detector is prepared using mature semiconductor packaging and lead technology.

[0123] In order to conduct performance testing of the terahertz detector of the present invention, the above-mentioned chemical vapor transport method can be used to synthesize NbS2 without Co element intercalation, and the above-mentioned terahertz detector preparation method can be used to prepare NbS2 without Co element intercalation into a terahertz detector, wherein all parameter conditions (thickness, size, etc.) are consistent with the above-mentioned embodiment to eliminate the influence of material size and thickness on the response performance.

[0124] The above-mentioned terahertz detector was tested, and the experiments showed that the response current and response speed of NbS2 with Co element intercalation were greatly improved, indicating that Co element intercalation is an effective way to improve the terahertz detection performance of NbS2 devices.

[0125] Examples 1 and 5 illustrate that Ni intercalation is an effective way to improve the terahertz detection performance of niobium disulfide devices, and other intercalation elements such as Co are also suitable for improving the terahertz detection performance of niobium disulfide devices.

[0126] Compared with the prior art, the terahertz detector and the method for preparing the terahertz detector according to the embodiments of the present invention modify the energy band structure, physical properties and carrier transport characteristics of the transition metal chalcogenide by element intercalation, and apply it to the terahertz detector, thereby achieving high-performance terahertz detection, which is a simple and easy way.

[0127] According to the terahertz detector and the method for preparing the terahertz detector according to the embodiments of the present invention, due to the unique properties brought about by element intercalation of transition metal chalcogenides, the transition metal chalcogenides after element intercalation are applied to the terahertz detector, so that the responsiveness and response speed of the terahertz detector are greatly improved at the same time, which is an effective way to improve the comprehensive performance of the terahertz detector.

[0128] According to the terahertz detector and the method for preparing the terahertz detector according to the embodiments of the present invention, by comparing the intrinsic properties of the material before and after element intercalation with the actual detection performance, the corresponding terahertz detection mechanism in the new material system can be further clarified.

[0129] According to the terahertz detector and its fabrication method according to the embodiments of the present invention, a simple chemical vapor transport (CVT) method is proposed for controllable element intercalation of transition metal chalcogenides, enabling the regulation of the band structure and physical properties of transition metal chalcogenides. The chemical vapor transport (CVT) method is simple to operate, low cost, high yield, and produces high-quality crystals, making it highly advantageous for the subsequent fabrication of novel optoelectronic devices and for studying the intrinsic physical properties of materials.

[0130] The present invention mainly uses single transition metal chalcogenides and transition metal chalcogenides after element intercalation for the preparation of terahertz detectors. Based on the symmetry-broken crystal structure, unique band structure and novel physical properties brought about by intercalation, a significant improvement in detector performance (responsivity and response time are improved by more than an order of magnitude) is achieved. At the same time, PPMS and ARPES can be used to specifically study the changes in transport properties and band structure before and after intercalation, attempting to correlate changes in the intrinsic properties of the material with changes in terahertz performance, and exploring new detection mechanisms that may exist in new material systems.

[0131] The foregoing descriptions of specific exemplary embodiments of the present invention are for purposes of illustration and description. These descriptions are not intended to limit the invention to the precise forms disclosed, and it is apparent that many variations and modifications are possible in light of the foregoing teachings. The exemplary embodiments have been selected and described for the purpose of explaining the specific principles of the invention and their practical application, thereby enabling those skilled in the art to realize and utilize a variety of exemplary embodiments of the invention and various options and modifications. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A terahertz detector, characterized in that: include: substrate; a channel material layer, the channel material layer being disposed on the substrate, wherein the channel material in the channel material layer comprises a transition metal chalcogenide compound undergoing element intercalation; an electrode, contacting the channel material layer; The chemical formula of the transition metal chalcogenide compound for element intercalation is P i MX2, where P is an intercalation element, M is a transition metal element, and X is a chalcogen element; The intercalation element is selected from metal or non-metal elements; the transition metal element is selected from: Nb or Ta; the chalcogen element is selected from: S or Se; the intercalation element is selected from: Ni, Co, Mn, V, Cr, Ge or In; Among them, the transition metal chalcogenide compound for element intercalation is prepared by chemical vapor transport method: in a vacuum environment, the intercalation element P, transition metal element M and chalcogenide element X are inversely grown at 850-900°C for three days in a stoichiometric ratio to obtain polycrystalline particles; the polycrystalline particles are forward grown at 950-830°C for seven days, and then the temperature is lowered to ambient temperature to obtain PiMX2 crystals.

2. The terahertz detector according to claim 1, wherein: The device also includes an antenna structure formed on the substrate and in contact with the channel material layer and the electrode.

3. A method for preparing a terahertz detector, characterized in that: include: providing a substrate; Providing a channel material, and transferring the channel material to the surface of the substrate to form a channel material layer; The channel material includes a transition metal chalcogenide compound for element intercalation, and the chemical formula of the transition metal chalcogenide compound for element intercalation is P i MX2, wherein P is an intercalation element, M is a transition metal element, and X is a chalcogenide element, wherein the intercalation element includes a metal or non-metal element, wherein the intercalation element is selected from: Ni, Co, Mn, V, Cr, Ge or In, wherein the transition metal element is selected from: Nb or Ta, and wherein the chalcogenide element is selected from: S or Se; wherein the transition metal chalcogenide compound-P for element intercalation is synthesized by a chemical vapor transport method i MX2; forming an electrode on the substrate, wherein the electrode is in contact with the channel material layer; The step of providing a channel material and transferring the channel material to the surface of the substrate to form a channel material layer includes: Preparation of channel material: In a vacuum environment, intercalation element P, transition metal element M and chalcogenide element X are grown at 850-900 ° C in a stoichiometric ratio for three days to obtain polycrystalline particles; the polycrystalline particles are grown at 950-830 ° C in a forward direction for seven days, and then the temperature is lowered to ambient temperature to obtain P i MX2 crystal; P i MX2 crystal is cleaved into P by mechanical exfoliation i MX2 nanosheets are transferred to the substrate surface.

4. The method for preparing a terahertz detector according to claim 3, wherein: A metal mark is formed on the substrate; After the step of transferring the channel material to the surface of the substrate to form a channel material layer, the method further includes recording the position of the channel material layer and the metal mark corresponding thereto.

5. The method for preparing a terahertz detector according to claim 4, wherein: The step of forming an electrode on the substrate, wherein the electrode contacts the channel material layer, comprises: An electrode is formed on the substrate, wherein the electrode connects the channel material layer and the metal mark.

6. The method for preparing a terahertz detector according to claim 3, wherein: The method further includes forming an antenna structure on the substrate, wherein the antenna structure is in contact with the channel material layer, and the electrode is connected to the antenna structure.

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