A flexible substrate material doped with a two-dimensional material and a method for manufacturing a sensor thereof

Abstract

The application discloses a kind of flexible substrate material of doped two-dimensional material and its preparation method of sensor, belong to array sensor technical field.The electrode material includes two-dimensional material base, composite doping atomic layer and insulating isolation layer, high-density defect sites are formed by H2 plasma treatment, uniform distribution of doping atoms is realized by atomic layer deposition, and self-aligned photolithography technology is used to accurately integrate electrode and temperature-sensitive layer.The scheme optimizes the electronic structure of two-dimensional material through the synergistic effect of composite doping, combined with multilayer heterojunction design and high-precision preparation process, significantly improves the response ability of the electrode to weak pressure signals, and realizes high resolution and stability of the sensor in pressure and temperature detection.The application has wide application prospect in the field of wearable devices, medical monitoring, robot tactile perception, etc.

Description

Technical Field

[0001] This invention relates to the field of electronic materials technology, specifically to a method for preparing a flexible substrate material doped with two-dimensional materials and its sensor. Background Technology

[0002] In the field of arrayed sensors, the performance of electrode materials directly affects the sensor's ability to capture weak signals and its resolution. Traditional electrode materials, such as metal thin films or carbon-based composite materials, suffer from low electron transport efficiency and insufficient surface active sites, making it difficult to meet the requirements of high-sensitivity pressure detection. Two-dimensional materials, such as graphene and molybdenum disulfide, are ideal choices for electrode materials due to their excellent electrical properties, large specific surface area, and atomic-level thickness; however, their intrinsic electronic structure limits their response to pressure signals. In existing technologies, single-element doping can improve the performance of two-dimensional materials, but problems such as poor doping uniformity and significant interlayer coupling effects limit the improvement in sensor resolution. Furthermore, the lack of synergistic design with temperature-sensitive layers and insulating layers makes it difficult to achieve accurate detection of multiple physical quantities. In addition, traditional fabrication processes suffer from low alignment accuracy and numerous interface defects when integrating electrodes with sensor functional layers, further affecting device performance. Therefore, there is an urgent need for a technical solution that optimizes the electronic structure of two-dimensional materials through composite doping systems and combines it with high-precision integration processes to overcome the bottlenecks in resolution and stability of existing sensors. Summary of the Invention

[0003] To address the limitations in existing technologies where single-element doping improves the performance of two-dimensional materials, such as poor doping uniformity and significant interlayer coupling effects leading to limited sensor resolution improvement, and the lack of synergistic design with temperature-sensitive and insulating layers hindering accurate detection of multiple physical quantities, this application provides a method for preparing a flexible substrate material doped with two-dimensional materials and its sensor.

[0004] In a first aspect, this application provides a flexible substrate material doped with two-dimensional materials, comprising: a two-dimensional material substrate, wherein the two-dimensional material is at least one of graphene, molybdenum disulfide, tungsten diselenide, or black phosphorus; a composite doped atomic layer, wherein the composite doped atoms include nitrogen and boron, the nitrogen and boron atomic doping ratio being 1:3 to 3:1, and the composite doped atoms being uniformly distributed on the surface of the two-dimensional material substrate and at grain boundary defects; and an insulating isolation layer, wherein the insulating isolation layer is boron nitride nanosheets or aluminum oxide thin film, covering the surface of the two-dimensional material substrate, and has a thickness of 5-20 nm.

[0005] In one embodiment, the two-dimensional material substrate is a heterojunction formed by graphene and MoS2, wherein the graphene layer in the heterojunction has a thickness of 1-3 atomic layers and the MoS2 layer has a thickness of 2-5 atomic layers, and the composite doped atoms are preferentially enriched at the edge active sites of the MoS2 layer.

[0006] In one embodiment, the total doping concentration of the composite doped atoms is from 1 × 10¹³ cm⁻² to 5 × 10¹³ cm⁻². 4 cm⁻², the surface work function of the two-dimensional material substrate is 4.2-5.1 eV, which can be continuously adjusted by adjusting the doping ratio of nitrogen and boron.

[0007] Secondly, the present invention also provides a method for fabricating a high-resolution arrayed sensor based on any of the electrode materials described in the present invention, comprising the following steps: two-dimensional material substrate pretreatment: transferring a two-dimensional material thin film onto a silicon or polyimide substrate, and treating it with H2 plasma, the treatment parameters being: H2 flow rate 60-120 mL / min, RF power 1.4-1.8 A, and treatment time 3-10 minutes; composite doping process: sequentially introducing NH3 and B2H6 gases at a flow ratio of 1:1 to 3:1, and performing atomic layer deposition at 200-400℃, with a deposition cycle of 50-200 times; preparation of an insulating layer: forming a BN nanosheet layer or an Al2O3 thin film on the surface of the doped two-dimensional material by spin coating or chemical vapor deposition, the thickness of which is controlled by the deposition time to 5-20 nm; defining an arrayed electrode pattern on the surface of a flexible substrate material using self-aligned photolithography, with a linewidth ≤10 μm, depositing a vanadium oxide thermosensitive layer with a thickness of 100-300 nm by electron beam evaporation, and connecting it to a signal processing ASIC chip through conductive vias with a diameter ≤5 μm.

[0008] In one embodiment, the purity of the NH3 gas is ≥99.999%, the partial pressure of the B2H6 gas is controlled at 1-5 Pa, and the substrate temperature fluctuation during the deposition process is ≤±5℃.

[0009] In one embodiment, when the two-dimensional material substrate is a graphene / MoS2 heterojunction, step H2 plasma treatment forms sulfur vacancy defects on the surface of the MoS2 layer, with a defect density of 1×10¹²cm⁻² to 5×10¹²cm⁻².

[0010] In one embodiment, the overlay accuracy of the self-aligned photolithography technique in the step is ≤2μm, a deep ultraviolet lithography light source with a wavelength of 248nm is used, and the edge alignment error between the electrode and the temperature-sensitive layer is ≤1μm. In one embodiment, the signal processing ASIC chip integrates a low-noise amplifier and a 24-bit Δ-Σ type A / D converter, and the aspect ratio of the conductive via is 5:1 to 10:1, filled with copper or gold.

[0011] In one embodiment, the step of constructing a gradient-doped heterostructure is further included: between a two-dimensional material substrate and an insulating isolation layer, the flow rate of atomic layer deposition gas is controlled in segments to form an N doping concentration gradient of 10%-90% and a B doping concentration gradient of 90%-10%, wherein the band offset ΔE of the gradient heterostructure is 0.3-0.8 eV.

[0012] In one embodiment, the arrayed electrode units of the sensor are distributed in an m×n matrix, where m and n ≥ 2. The size of a single electrode unit is 20μm×20μm to 50μm×50μm, the unit spacing is 50μm to 100μm, and adjacent electrode units are isolated by a silicon dioxide insulating layer with a thickness of 1-5μm.

[0013] Furthermore, when the two-dimensional material substrate is black phosphorus, the composite doping atoms also include sulfur, forming an NBS ternary doping system, with the S atomic doping ratio being N:B:S = 1:1:1 to 1:3:1. The sensor also includes a flexible encapsulation layer, the encapsulation layer material being polydimethylsiloxane or epoxy resin, with a thickness of 50-200 μm. The surface of the encapsulation layer has microstructure protrusions with a height of 50-100 μm and a spacing of 200-500 μm. When the two-dimensional material substrate is tungsten diselenide, the doping depth of the composite doping atoms is 5-20 nm, and the defect density is controlled by adjusting the H2 plasma treatment time. During the preparation of the Al2O3 thin film by chemical vapor deposition, the reactant gases are trimethylaluminum and deionized water, the deposition temperature is 150-250℃, and the deposition rate is 0.1-0.5 nm / cycle. The vanadium oxide thermosensitive layer has a crystal orientation of a crystal plane, and preferential growth is achieved by controlling the annealing temperature to 400-600℃ and the time to 30-90 minutes.

[0014] This invention significantly improves the performance of two-dimensional material electrodes and sensors through the synergistic optimization of composite doping systems and multilayer structure design. Regarding electrode materials, the composite doping of nitrogen and boron forms a double-doped defect structure on the surface and at grain boundary defects of the two-dimensional material. Compared to single doping, this effectively controls the electronic structure and surface active site distribution of the material, enhancing the carrier migration capability induced by pressure signals, thereby improving the electrode's response sensitivity to weak pressure changes. The introduction of an insulating isolation layer reduces interlayer electrical interference. Combined with the band shift design of the gradient-doped heterojunction, it forms an efficient charge transport path, reducing signal loss and improving the signal-to-noise ratio. In terms of fabrication processes, the combination of H2 plasma pretreatment and atomic layer deposition achieves atomically uniform distribution of doped atoms, overcoming the diffusion inhomogeneity problem of traditional doping processes and ensuring the consistency of material performance. The precise integration of self-aligned photolithography and conductive vias reduces alignment errors between the electrodes and the temperature-sensitive layer, reducing parasitic capacitance and improving signal transmission efficiency. The combination of the arrayed electrode unit design and the flexible encapsulation layer not only improves spatial resolution but also enhances the device's environmental adaptability and mechanical stability. The overall solution, through the deep integration of material modification, structural innovation and process optimization, breaks through the limitations of existing two-dimensional material sensors in terms of resolution, stability and integration accuracy, and provides an efficient solution for the accurate detection of multiple physical quantities in complex scenarios. It has significant application value and technological advantages in fields such as intelligent equipment and medical health. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a cross-sectional structure of a flexible substrate material doped with two-dimensional materials provided in an embodiment of this application;

[0016] Figure 2 This is a diagram illustrating the working steps of a preparation method provided in an embodiment of this application. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, specific embodiments of this application will be described in further detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely for explaining this application and not for limiting it. It should also be noted that, for ease of description, only the parts relevant to this application are shown in the drawings, not all of them. Before discussing exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe operations (or steps) as being processed sequentially, many of these operations can be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the operations can be rearranged. A process can be terminated when its operation is completed, but it may also have additional steps not included in the drawings. A process can correspond to a method, function, procedure, subroutine, subroutine, etc.

[0018] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0019] In the field of arrayed sensors, the performance of electrode materials directly affects the sensor's ability to capture weak signals and its resolution. Traditional electrode materials, such as metal thin films or carbon-based composite materials, suffer from low electron transport efficiency and insufficient surface active sites, making it difficult to meet the requirements of high-sensitivity pressure detection. Two-dimensional materials, such as graphene and molybdenum disulfide, are ideal choices for electrode materials due to their excellent electrical properties, large specific surface area, and atomic-level thickness; however, their intrinsic electronic structure limits their response to pressure signals. In existing technologies, single-element doping can improve the performance of two-dimensional materials, but problems such as poor doping uniformity and significant interlayer coupling effects limit the improvement in sensor resolution. Furthermore, the lack of synergistic design with temperature-sensitive layers and insulating layers makes it difficult to achieve accurate detection of multiple physical quantities. In addition, traditional fabrication processes suffer from low alignment accuracy and numerous interface defects when integrating electrodes with sensor functional layers, further affecting device performance. Therefore, there is an urgent need for a technical solution that optimizes the electronic structure of two-dimensional materials through composite doping systems and combines it with high-precision integration processes to overcome the bottlenecks in resolution and stability of existing sensors.

[0020] Therefore, this invention discloses a flexible substrate material doped with two-dimensional materials and a method for fabricating its sensor, belonging to the field of arrayed sensor technology. The electrode material comprises a two-dimensional material substrate, a composite doped atomic layer, and an insulating layer. High-density defect sites are formed through H2 plasma treatment, and uniform distribution of doped atoms is achieved by atomic layer deposition. The electrode and temperature-sensitive layer are precisely integrated using self-aligned photolithography. This approach optimizes the electronic structure of the two-dimensional material through the synergistic effect of composite doping. Combined with multilayer heterojunction design and high-precision fabrication processes, it significantly improves the electrode's response to weak pressure signals, achieving high resolution and stability in pressure and temperature detection. This invention has broad application prospects in wearable devices, medical monitoring, and robotic tactile sensing.

[0021] This embodiment provides a detailed description of the preparation method of flexible substrate materials doped with two-dimensional materials and their sensors, in order to achieve the technical solutions described in the claims.

[0022] Example 1

[0023] refer to Figure 1 The flexible substrate material doped with two-dimensional materials includes:

[0024] 101. An insulating layer, covering the entire surface of the two-dimensional material substrate and the composite doped atomic layer (corresponding to the uppermost region of the cross-section). It is prepared using boron nitride nanosheets and / or alumina thin films, with the thickness precisely controlled between 5 and 20 nm, acting as an "insulating barrier" to prevent unnecessary electrical interference between the electrodes and external circuits / dielectrics.

[0025] 102. A composite doped atomic layer is attached to the surface of a two-dimensional material substrate, while simultaneously penetrating and filling the grain boundary defects inside the substrate (i.e., the microscopic gaps and defects of the substrate are covered by doped atoms). It is composed of nitrogen (N) and boron (B) atoms, with the atomic doping ratio strictly controlled between 1:3 and 3:1, to achieve atomic-level composite modification and optimize the electrical performance of the electrode.

[0026] 103. Two-dimensional material substrate, the basic support layer of the structure, adopts at least one two-dimensional material selected from graphene, molybdenum disulfide, tungsten diselenide, and black phosphorus, and utilizes its ultrathin and high conductivity properties to construct the electrode framework.

[0027] The electrode material uses a two-dimensional material as a substrate, including at least one of graphene, molybdenum disulfide (MoS2), tungsten diselenide (WSe2), or black phosphorus (BP). A defect-controlled structure is formed through composite doping of nitrogen (N) and boron (B). Taking a graphene / MoS2 heterojunction electrode as an example, the bottom layer is 1-3 atomic-layer-thick graphene, providing a high-speed electron transport channel. The upper layer is 2-5 atomic-layer-thick MoS2, utilizing its edge active sites to preferentially enrich dopant atoms. The composite doped atoms are uniformly distributed on the surface of the two-dimensional material and at grain boundary defects in an atomic layer deposition (ALD) technique, achieving atomic-level uniform doping and forming a double-doped defect structure, significantly improving the surface activity and electron transport efficiency of the material. The insulating layer uses 5-20 nm thick boron nitride (BN) nanosheets or alumina (Al2O3) films, bonded to the two-dimensional material substrate through van der Waals forces or covalent bonds, suppressing interlayer electrical interference and protecting the electrode structure.

[0028] Two-dimensional material films (such as graphene and MoS2 heterojunctions) are wet-transferred or directly grown on substrates such as silicon (Si) and polyimide (PI), and high-density defect sites are constructed using H2 plasma treatment. Taking a graphene / MoS2 heterojunction on a silicon substrate as an example, the H2 flow rate is controlled at 60-120 mL / min, the RF power is 1.4-1.8 A, and the treatment time is 3-10 minutes. Sulfur (S) vacancy defects are formed on the surface of the MoS2 layer, with a defect density of 1×10¹² cm⁻² to 5×10¹² cm⁻², providing anchoring sites for subsequent doping atoms. This process achieves precise control of defect density and distribution by adjusting plasma parameters, ensuring uniform adsorption of doping atoms. NH3 and B₂H₆ gases are sequentially introduced into an atomic layer deposition (ALD) apparatus at a flow ratio of 1:1 to 3:1, and ALD is performed at 200-400℃ for 50-200 deposition cycles, achieving synergistic doping of nitrogen and boron atoms. Taking black phosphorus-based electrodes as an example, sulfur (S) is introduced to form an NBS ternary doping system. By segmentally controlling the gas flow rate, a gradient-doped heterojunction is constructed between the two-dimensional material substrate and the insulating isolation layer: the N doping concentration in the bottom layer is gradually increased from 10% to 90%, while the B doping concentration in the top layer is correspondingly decreased from 90% to 10%, forming a band shift (ΔE) of 0.3-0.8 eV, which promotes the directional migration of charge carriers and signal separation. During the doping process, the purity of NH3 gas is ≥99.999%, the partial pressure of B2H6 gas is controlled at 1-5 Pa, and the substrate temperature fluctuation is ≤±5℃, ensuring that the doping uniformity error is ≤±5%.

[0029] The arrayed electrode pattern is defined using self-aligned photolithography, with a linewidth ≤10μm and an overlay accuracy ≤2μm. Precise alignment between the electrode and the temperature-sensitive layer (such as vanadium oxide VO2) is achieved using a deep ultraviolet (DUV) lithography source (wavelength 248nm), with an edge alignment error ≤1μm. Taking the preparation of the vanadium oxide temperature-sensitive layer as an example, a thin film of 100-300nm thickness is deposited on the electrode surface using electron beam evaporation or pulsed laser deposition. After annealing at 400-600℃, preferential growth of the (110) crystal plane is achieved, improving temperature response sensitivity. Conductive vias are filled with copper (Cu) or gold (Au) with a diameter ≤5μm, an aspect ratio of 5:1 to 10:1, and a contact resistance ≤100mΩ, ensuring low-noise connection with the signal processing chip ASIC.

[0030] The sensor surface is covered with a flexible encapsulation layer (such as polydimethylsiloxane PDMS or epoxy resin) with a thickness of 50-200 μm. Microstructure protrusions with a height of 50-100 μm and a spacing of 200-500 μm are fabricated on the surface using micromolding technology to enhance pressure transmission efficiency. For high-humidity applications, the encapsulation layer surface is coated with a nanoscale moisture-proof coating (such as polytetrafluoroethylene PTFE) with a water vapor permeability of less than 5 × 10⁻¹³ g / (cm²・s), and a humidity compensation electrode is integrated. Differential detection is used to correct for environmental interference in real time, ensuring the sensor's stability in complex environments.

[0031] In some embodiments, graphene is first selected as the two-dimensional material substrate for composite doping during the preparation process. The two-dimensional graphene substrate is treated with hydrogen plasma, during which the gas flow rate is controlled at 60 to 120 mL / min and the radio frequency power is set to 1.4 to 1.8 A to ensure sufficient exposure of active sites on the graphene surface. After this pretreatment, the surface of the two-dimensional material substrate has appropriate surface energy, which facilitates subsequent doping. Atomic layer deposition (ALD) doping is performed using nitrogen and boron gases. In this step, the flow ratio of nitrogen to boron gases is controlled at 1:1 to 3:1, and the gas deposition is carried out at a temperature of 200 to 400°C. Each deposition cycle is 50 to 200 times to ensure the uniformity and hierarchical structure of the doping. After this process, nitrogen and boron dopants are preferentially distributed on the surface of graphene and at grain boundary defects, with a doping ratio of 1:3 to 3:1, ultimately resulting in a composite-doped electrode material with high conductivity and good stability. Subsequently, boron nitride nanosheets were formed on the surface of the two-dimensional material using spin coating, or aluminum oxide (Al2O3) films were deposited on the material surface using chemical vapor deposition (CVD). The thickness of the insulating layer was controlled between 5 and 20 nm to improve the stability and signal transmission performance of the sensor. The array fabrication of the sensor employed self-aligned photolithography. First, an array of electrode patterns was defined on the surface of the electrode material, ensuring that the linewidth of the patterns did not exceed 10 μm. A vanadium oxide thermosensitive layer with a thickness between 100 and 300 nm was then deposited by electron beam evaporation. The thermosensitive layer enhances the temperature response of the sensor signal, further improving its resolution. Then, the electrodes were connected to the signal processing chip (ASIC) through conductive vias with a diameter not exceeding 5 μm to ensure the efficiency and accuracy of the signal transmission process. Finally, the array electrode units of the sensor were distributed in an m×n matrix, with individual electrode unit sizes ranging from 20 μm × 20 μm to 50 μm × 50 μm. Adjacent units were isolated by a silicon dioxide insulating layer with a thickness of 1 to 5 μm. With this design, we can achieve higher resolution sensor arrays suitable for fine detection and a variety of sensing applications.

[0032] This embodiment introduces a method for fabricating two-dimensional material electrodes with gradient doping, and further explores its application in high-resolution arrayed sensors.

[0033] refer to Figure 2 Secondly, the present invention also provides a method for fabricating a high-resolution arrayed sensor based on any of the electrode materials described in the present invention, comprising the following steps: two-dimensional material substrate pretreatment: transferring a two-dimensional material thin film onto a silicon or polyimide substrate, and treating it with H2 plasma, the treatment parameters being: H2 flow rate 60-120 mL / min, RF power 1.4-1.8 A, and treatment time 3-10 minutes; composite doping process: sequentially introducing NH3 and B2H6 gases at a flow ratio of 1:1 to 3:1, and performing atomic layer deposition at 200-400℃, with a deposition cycle of 50-200 times; preparation of an insulating isolation layer: forming a BN nanosheet layer or an Al2O3 thin film on the surface of the doped two-dimensional material by spin coating or chemical vapor deposition, the thickness being controlled by the deposition time to 5-20 nm; defining an arrayed electrode pattern on the surface of a flexible substrate material using self-aligned photolithography, with a linewidth ≤10 μm, depositing a vanadium oxide thermosensitive layer with a thickness of 100-300 nm by electron beam evaporation, and connecting it to a signal processing ASIC chip through conductive vias with a diameter ≤5 μm.

[0034] This method ensures the sensor's performance and stability through a series of process steps. First, in the pretreatment stage of the two-dimensional material substrate, a two-dimensional material film is transferred onto a silicon or polyimide substrate and treated with H2 plasma. The treatment parameters are controlled as follows: H2 flow rate in the range of 60 to 120 mL / min, RF power set to 1.4 to 1.8 A, and treatment time controlled between 3 and 10 minutes, to ensure that the chemical activity of the two-dimensional material surface is suitable for subsequent processes. Next, in the composite doping process, ammonia (NH3) and diborane (B2H6) gases are sequentially introduced, with a flow ratio controlled between 1:1 and 3:1, and atomic layer deposition (ALD) is performed at a temperature of 200 to 400 °C. The deposition cycle is set between 50 and 200 times, thereby ensuring uniform distribution of dopant elements and optimizing the electronic properties of the material.

[0035] In the insulating layer preparation stage, a BN nanosheet or Al2O3 thin film is formed on the surface of the doped two-dimensional material using spin coating or chemical vapor deposition (CVD) technology. The film thickness is controlled between 5 and 20 nm by the deposition time to achieve good electrical insulation. Subsequently, self-aligned photolithography is used to define the arrayed electrode pattern, with the electrode linewidth controlled within 10 μm. High precision is required, with an overlay error not exceeding 2 μm. Deep ultraviolet lithography (248 nm) is used as the light source to ensure high-precision pattern transfer. The alignment error between the electrode and the temperature-sensitive layer is required to be no more than 1 μm. During the electrode deposition process, a vanadium oxide (VOx) temperature-sensitive layer is deposited using electron beam evaporation technology. The thickness of the temperature-sensitive layer is controlled between 100 and 300 nm, and it is connected to the signal processing ASIC chip through conductive vias with a diameter not exceeding 5 μm to ensure efficient signal transmission and low noise.

[0036] In some embodiments, the purity of the ammonia (NH3) used is required to be ≥99.999%, while the partial pressure of diborane gas (B2H6) is controlled to be 1 to 5 Pa. The substrate temperature fluctuation during deposition does not exceed ±5°C, thus ensuring high material quality. Specifically, in the case of a graphene / MoS2 heterojunction, H2 plasma treatment forms sulfur vacancy defects on the surface of the MoS2 layer, with the defect density controlled between 1×10¹² cm⁻² and 5×10¹² cm⁻², optimizing the material's conductivity and the sensor's response speed.

[0037] Furthermore, this invention also relates to a method for manufacturing a gradient-doped heterostructure. Between a two-dimensional material substrate and an insulating layer, by segmentally controlling the flow rate of atomic layer deposition gas, the N-doping concentration gradient is gradually increased from 10% to 90%, while the B-doping concentration gradient is gradually decreased from 90% to 10%. The band shift (ΔE) of the gradient heterostructure is controlled between 0.3 and 0.8 eV, thereby further enhancing the sensitivity and selectivity of the sensor.

[0038] In terms of signal processing, the sensor integrates a low-noise amplifier and a 24-bit Δ-Σ type A / D converter to ensure the accuracy and stability of signal processing. The aspect ratio of the conductive vias is set between 5:1 and 10:1, and they are filled with copper or gold to ensure efficient and stable current transmission. Finally, the arrayed electrode units of the sensor are distributed in an m×n matrix, where m and n ≥ 2. The size of a single electrode unit is controlled between 20μm×20μm and 50μm×50μm, and the unit spacing is between 50μm and 100μm. Adjacent electrode units are isolated by a silicon dioxide insulating layer with a thickness controlled between 1 and 5μm to ensure signal independence and clear transmission between electrodes.

[0039] In one embodiment, the purity of the NH3 gas is ≥99.999%, the partial pressure of the B2H6 gas is controlled at 1-5 Pa, and the substrate temperature fluctuation during the deposition process is ≤±5℃.

[0040] In one embodiment, when the two-dimensional material substrate is a graphene / MoS2 heterojunction, step H2 plasma treatment forms sulfur vacancy defects on the surface of the MoS2 layer, with a defect density of 1×10¹²cm⁻² to 5×10¹²cm⁻².

[0041] The overlay accuracy of the self-aligned photolithography technique in this step is ≤2μm, a deep ultraviolet lithography light source with a wavelength of 248nm is used, and the edge alignment error between the electrode and the temperature-sensitive layer is ≤1μm. In one embodiment, the signal processing ASIC chip integrates a low-noise amplifier and a 24-bit Δ-Σ type A / D converter, and the aspect ratio of the conductive via is 5:1 to 10:1, filled with copper or gold.

[0042] In one embodiment, the step of constructing a gradient-doped heterostructure is further included: between a two-dimensional material substrate and an insulating isolation layer, the flow rate of atomic layer deposition gas is controlled in segments to form an N doping concentration gradient of 10%-90% and a B doping concentration gradient of 90%-10%, wherein the band offset ΔE of the gradient heterostructure is 0.3-0.8 eV.

[0043] In one embodiment, the arrayed electrode units of the sensor are distributed in an m×n matrix, where m and n ≥ 2. The size of a single electrode unit is 20μm×20μm to 50μm×50μm, the unit spacing is 50μm to 100μm, and adjacent electrode units are isolated by a silicon dioxide insulating layer with a thickness of 1-5μm.

[0044] Furthermore, when the two-dimensional material substrate is black phosphorus, the composite doping atoms also include sulfur, forming an NBS ternary doping system, with the S atomic doping ratio being N:B:S = 1:1:1 to 1:3:1. The sensor also includes a flexible encapsulation layer, the encapsulation layer material being polydimethylsiloxane or epoxy resin, with a thickness of 50-200 μm. The surface of the encapsulation layer has microstructure protrusions with a height of 50-100 μm and a spacing of 200-500 μm. When the two-dimensional material substrate is tungsten diselenide, the doping depth of the composite doping atoms is 5-20 nm, and the defect density is controlled by adjusting the H2 plasma treatment time. During the preparation of the Al2O3 thin film by chemical vapor deposition, the reactant gases are trimethylaluminum and deionized water, the deposition temperature is 150-250℃, and the deposition rate is 0.1-0.5 nm / cycle. The vanadium oxide thermosensitive layer has a crystal orientation of a crystal plane, and preferential growth is achieved by controlling the annealing temperature to 400-600℃ and the time to 30-90 minutes.

[0045] In this embodiment, graphene was selected as the two-dimensional material substrate, and a nitrogen and boron gradient doping structure was formed by segmentally controlling the gas flow rate during atomic layer deposition (ALD). Specifically, the nitrogen doping concentration gradually increased from 10% to 90%, while the boron doping concentration gradually decreased from 90% to 10%. This gradient doping structure not only enhances the conductivity of the electrode but also significantly improves its stability and response speed.

[0046] To ensure the uniformity and gradient of the doping effect, the gas flow rate was precisely controlled during the doping process, with a gas flow ratio ranging from 1:1 to 3:1, and the deposition temperature was maintained between 200 and 400°C. During this process, the doping ratio and distribution of nitrogen and boron were gradually achieved by controlling the gas flow rate, thus achieving a good gradient doping effect. To enhance the stability of the electrode material, boron nitride nanosheets and alumina films were further deposited on the surface of the two-dimensional material as insulating layers, with a thickness of 5 to 20 nm. Subsequently, boron nitride nanosheet layers or Al₂O₃ films were formed on the surface using spin coating and CVD technology. These films ensured the long-term stable operation of the sensor.

[0047] Through the above steps, this embodiment ultimately obtained a two-dimensional material electrode with a well-developed gradient doping structure and successfully applied it to the fabrication of a high-resolution arrayed sensor. The arrayed design of the sensor employed self-aligned photolithography, and a vanadium oxide thermosensitive layer was deposited via electron beam evaporation to ensure the sensor's temperature response performance met expectations. By precisely controlling the size and spacing of the electrode patterns, we achieved a higher-resolution sensor array suitable for various high-precision detection tasks.

[0048] Through the aforementioned technical solutions, the performance of two-dimensional material electrodes and sensors is significantly improved through the synergistic optimization of composite doping systems and multilayer structure designs. Regarding electrode materials, the composite doping of nitrogen and boron forms a double-doped defect structure on the surface and at grain boundary defects of the two-dimensional material. Compared to single doping, this effectively controls the electronic structure and surface active site distribution of the material, enhancing the carrier migration capability induced by pressure signals, thereby improving the electrode's response sensitivity to weak pressure changes. The introduction of an insulating isolation layer reduces interlayer electrical interference. Combined with the bandgap design of the gradient-doped heterojunction, it forms an efficient charge transport path, reducing signal loss and improving the signal-to-noise ratio. In terms of fabrication processes, the combination of H2 plasma pretreatment and atomic layer deposition achieves atomically uniform distribution of doped atoms, overcoming the diffusion inhomogeneity problem of traditional doping processes and ensuring the consistency of material performance. The precise integration of self-aligned photolithography and conductive vias reduces alignment errors between the electrodes and the temperature-sensitive layer, reduces parasitic capacitance, and improves signal transmission efficiency. The combination of the arrayed electrode unit design and the flexible encapsulation layer not only improves spatial resolution but also enhances the device's environmental adaptability and mechanical stability. The overall solution, through the deep integration of material modification, structural innovation and process optimization, breaks through the limitations of existing two-dimensional material sensors in terms of resolution, stability and integration accuracy, and provides an efficient solution for the accurate detection of multiple physical quantities in complex scenarios. It has significant application value and technological advantages in fields such as intelligent equipment and medical health.

[0049] The above description is merely a preferred embodiment and the technical principles employed in this application. This application is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions that can be made by those skilled in the art will not depart from the scope of protection of this application. Therefore, although this application has been described in detail through the above embodiments, this application is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of this application. The scope of this application is determined by the scope of the claims.

Claims

1. A flexible substrate material doped with two-dimensional materials, characterized in that, include: A two-dimensional material substrate, wherein the two-dimensional material is at least one of graphene, molybdenum disulfide, tungsten diselenide, or black phosphorus; A composite doped atomic layer, wherein the composite doped atoms include nitrogen and boron, and the atomic doping ratio of nitrogen to boron is 1:3 to 3:1, and the composite doped atoms are uniformly distributed on the surface of the two-dimensional material substrate and at grain boundary defects; An insulating layer, which is boron nitride nanosheets and / or aluminum oxide film, is applied to the surface of the two-dimensional material substrate and has a thickness of 5-20 nm.

2. The flexible substrate material according to claim 1, characterized in that, The two-dimensional material substrate is a heterojunction formed by graphene and MoS2. The graphene layer in the heterojunction has a thickness of 1-3 atomic layers, and the MoS2 layer has a thickness of 2-5 atomic layers. The composite doped atoms are preferentially enriched at the edge active sites of the MoS2 layer.

3. The flexible substrate material according to claim 1, characterized in that, The total doping concentration of the composite doped atoms is from 1×10¹³ cm⁻² to 5×10¹³ cm⁻². 4 cm⁻², the surface work function of the two-dimensional material substrate is 4.2-5.1 eV, which can be continuously adjusted by adjusting the doping ratio of nitrogen and boron.

4. A method for fabricating a high-resolution arrayed sensor based on the flexible substrate material according to any one of claims 1-3, characterized in that, Includes the following steps: Two-dimensional material substrate pretreatment: The two-dimensional material film is transferred onto a silicon and / or polyimide substrate and treated with H2 plasma. The treatment parameters are: H2 flow rate 60-120 mL / min, radio frequency power 1.4-1.8 A. NH3 and B2H6 gases are introduced sequentially at a flow ratio of 1:1 to 3:1, and atomic layer deposition is carried out at 200-400℃, with a deposition cycle of 50-200 times. Boron nitride nanosheets and / or Al2O3 films are formed on the surface of doped two-dimensional materials by spin coating and / or chemical vapor deposition, with the thickness controlled to be 5-20 nm by the deposition time. An array of electrode patterns with a linewidth ≤10μm is defined on the surface of a flexible substrate material using self-aligned photolithography. A vanadium oxide thermosensitive layer with a thickness of 100-300nm is deposited by electron beam evaporation and connected to the signal processing chip ASIC through conductive vias with a diameter ≤5μm.

5. The preparation method according to claim 4, characterized in that, During the process, the purity of NH3 gas is ≥99.999%, the partial pressure of B2H6 gas is controlled at 1-5 Pa, and the substrate temperature fluctuation during deposition is ≤±5℃.

6. The preparation method according to claim 4, characterized in that, When the two-dimensional material substrate is a graphene / MoS2 heterojunction, H2 plasma treatment forms sulfur vacancy defects on the surface of the MoS2 layer, with a defect density of 1×10¹²cm⁻²~5×10¹²cm⁻².

7. The preparation method according to claim 4, characterized in that, The overlay accuracy of self-aligned lithography is ≤2μm, using a deep ultraviolet lithography light source with a wavelength of 248nm, and the edge alignment error between the electrode and the temperature-sensitive layer is ≤1μm.

8. The preparation method according to claim 4, characterized in that, The signal processing chip ASIC integrates a low-noise amplifier and a 24-bit A / D converter. The aspect ratio of the conductive via is 5:1 to 10:1, and it is filled with a filler.

9. The preparation method according to claim 6, characterized in that, It also includes the step of building a gradient-doped heterostructure: between the two-dimensional material substrate and the insulating isolation layer, the flow rate of atomic layer deposition gas is controlled in segments to form an N doping concentration gradient of 10%-90% and a B doping concentration gradient of 90%-10%, and the band shift ΔE of the gradient heterostructure is 0.3-0.8eV.

10. The preparation method according to claim 4, characterized in that, The arrayed electrode units of the sensor are distributed in an m×n matrix, where m and n ≥ 2. The size of a single electrode unit is 20μm×20μm to 50μm×50μm, and the unit spacing is 50μm to 100μm. Adjacent electrode units are isolated by a silicon dioxide insulating layer with a thickness of 1-5μm.

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