Construction method of high-spin-selectivity photoelectric detector

Abstract

The invention relates to a construction method of a high-spin-selectivity photoelectric detector, and the method comprises the steps: setting a scattering region in the middle of a photoelectric detector model constructed by an armchair type Janus WSSe lattice, and enabling the regions at the two ends to serve as a left electrode and a right electrode respectively; the method comprises the following steps: introducing a vacancy defect of a single atomic level into a scattering region of a photoelectric detector, carrying out electronic local state analysis and impurity doping analysis on the scattering region after the defect is introduced, and screening out transition metal elements meeting preset conditions as doping elements; and performing bias voltage regulation and control on the photoelectric detector doped with the elements to construct a cooperative regulation and control strategy so as to complete construction of the photoelectric detector. According to the invention, through atomic scale defect introduction and transition metal doping modes, the photo-generated spinning current intensity, the spinning polarizability and the selective response ability to polarized light are significantly improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a method for constructing a highly spin-selective photodetector. Background Technology

[0002] With the rapid development of information technology and optoelectronic technology, photodetectors, as crucial devices for photoelectric conversion, play a key role in fields such as communication, imaging, sensing, and quantum information. Traditional photodetectors primarily focus on the intensity response of photocurrent; however, with the development of spintronics, spin-selective detectors have attracted widespread attention. Spin-selective photodetectors not only achieve high-sensitivity photocurrent response but also enable deeper manipulation and processing of optical information by controlling and detecting electron spin states, greatly enhancing the functionality and application value of the devices.

[0003] Two-dimensional materials, due to their unique electronic structure and excellent photoelectric properties, have become ideal material systems for constructing high-performance photodetectors. In particular, Janus two-dimensional materials, due to their top-bottom structural asymmetry, can naturally break spatial inversion symmetry, making them an important candidate material for realizing the spin photoelectric effect (SPGE).

[0004] However, current spin photodetectors based on Janus materials face problems such as poor spin selectivity, low photoelectric response intensity, and narrow response frequency bands, necessitating optimization at the material design level. Therefore, developing novel high spin-selective photodetectors based on Janus WSSe monolayer materials has significant theoretical importance and broad application prospects. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a method for constructing a highly spin-selective photodetector.

[0006] A method for constructing a highly spin-selective photodetector, comprising:

[0007] Step 1: Select an armchair-shaped lattice of Janus WSSe monolayer material with asymmetric boundary structure as the basic configuration;

[0008] Step 2: Select the middle region of the basic configuration as the scattering region of the photodetector, and use the armchair-shaped lattice structures at both ends connected to the scattering region as the left and right leads of the photodetector, respectively.

[0009] Step 3: Introduce single-atom-level vacancy defects into the scattering region of the photodetector, and perform electronic localization state analysis on the scattering region after defect introduction to obtain the analysis results;

[0010] Step 4: When the analysis results meet the set criteria, a transition metal element is introduced as a substitute atom at the tungsten atom sites of the Janus WSSe nanoribbon structure in the scattering region to form a doping model;

[0011] Step 5: Analyze the stability and band structure of the doping model under different transition metal elements and select transition metal elements that meet the preset conditions as doping elements.

[0012] Step 6: Implement a bias control strategy for the doped photodetector.

[0013] Preferably, in step 3, the single-atom-level vacancy defects include: sulfur vacancies, selenium vacancies, and sulfur-selenium exchange defects.

[0014] Preferably, the method further includes: in step 3, calculating the total density of states and the projected density of states of each atomic orbital in the scattering region after the defect is introduced using density functional theory, in order to complete the analysis of the electronic localized states of the scattering region.

[0015] Preferably, step 5 includes:

[0016] Calculate the doping formation energy of the doping model under different transition metal elements to determine the thermodynamic stability of the doped metal element;

[0017] The spin-polarized band structure of the doped model was calculated, and the degree of spin splitting in the band was evaluated.

[0018] When the thermodynamic stability and spin splitting degree of the doped metal element meet the preset conditions, the corresponding metal element is used as the doping element.

[0019] Preferably, the formula for calculating the doping formation energy is:

[0020] E form =E doped -E pure +μw-μx

[0021] Among them, E form E represents the doping formation energy. doped E represents the total energy of the doped structure. pure μw represents the total energy of the pure structure, μx represents the chemical potential of the tungsten atom, and μx represents the chemical potential of the dopant element x.

[0022] The present invention also provides a system for constructing a highly spin-selective photodetector, comprising:

[0023] The basic configuration determination module is used to select an armchair-shaped lattice with an asymmetric boundary structure as the basic configuration in the nanoribbon structure of Janus WSSe monolayer material;

[0024] A preliminary construction module for a photodetector is used to select the middle region of the basic configuration as the scattering region of the photodetector, and the armchair-shaped lattice structures at both ends connected to the scattering region are used as the left and right leads of the photodetector, respectively.

[0025] The electronic localized state analysis module is used to introduce single-atom-level vacancy defects into the scattering region of a photodetector and perform electronic localized state analysis on the scattering region after the defect is introduced to obtain the analysis results.

[0026] The impurity doping module is used to introduce transition metal elements as substitute atoms into the tungsten atom sites of the Janus WSSe nanobelt structure in the scattering region to form a doping model when the analysis results meet the set standards.

[0027] The doping element determination module is used to analyze the stability and band structure of the doping model under different transition metal elements and select transition metal elements that meet the preset conditions as doping elements.

[0028] The bias control module is used to control the bias of the photodetector after doping with elements to construct a synergistic control strategy.

[0029] The present invention also provides an electronic device, including a bus, a transceiver, a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the transceiver, the memory, and the processor are connected via the bus, characterized in that the computer program, when executed by the processor, implements the steps in the above-described method for constructing a high spin-selective photodetector.

[0030] The present invention also provides a computer-readable storage medium having a computer program stored thereon, characterized in that the computer program, when executed by a processor, implements the steps in the above-described method for constructing a high spin-selective photodetector.

[0031] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0032] This invention relates to a method for constructing a highly spin-selective photodetector. Compared with the prior art, this invention significantly improves the intensity of photogenerated spin current, spin polarization, and selective response to polarized light by introducing atomic-scale defects and transition metal doping.

[0033] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 The top and side views of the Janus WSSe device provided by this invention show different defect structure layouts (including vacancies, exchange defects, and doping sites).

[0036] Figure 2 The band structure of the intrinsic WSSe material provided by this invention.

[0037] Figure 3 The projected density of states of the intrinsic WSSe material provided by this invention.

[0038] Figure 4 The present invention provides a band structure for a single-layer WSSe with different intrinsic defects.

[0039] Figure 5 The projected density of states of a monolayer WSSe under different intrinsic defects is provided for the present invention.

[0040] Figure 6 The present invention provides the band structure of a monolayer WSSe with different doping defects.

[0041] Figure 7 The projected density of states of monolayer WSSe under different doping defects is provided by the present invention.

[0042] Figure 8 This invention provides the relationship between the spin photocurrent R of WSSe nanoribbons under linearly polarized light and the polarization angle θ. The downward and upward triangles represent the spin-down and spin-up photocurrents, respectively. The six central regions analyzed are: pure WSSe (black solid line), Fe-substituted W (red solid line), Co-substituted W (green solid line), Ni-substituted W (blue solid line), S vacancy (red dashed line), Se vacancy (green dashed line), and Se-S exchange (blue dashed line). The incident photon energies are 1.8 eV, 2.4 eV, 3.4 eV, and 3.8 eV, respectively.

[0043] Figure 9 The maximum spin photocurrent under different doping conditions is shown in this invention as a function of photon energy.

[0044] Figure 10The spin polarizability η provided for this invention varies with light energy eV and incident light polarization angle θ. Seven central regions are considered: pure WSSe (black solid line), Fe-substituted W (red solid line), Co-substituted W (green solid line), Ni-substituted W (blue solid line), S vacancy (red dashed line), Se vacancy (green dashed line), and Se-S exchange (blue dashed line).

[0045] Figure 11 The curves showing the extinction ratio as a function of photon energy under different doping conditions provided by this invention.

[0046] Figure 12 The graph shows the relationship between spin-polarized photocurrent and bias voltage of the WSSe material with Ni atoms substituted at the W site provided by this invention under different photon energies. In the graph, the sine triangles represent the upper spin component, and the inverted triangles represent the lower spin component.

[0047] Figure 13 The device structure diagram provided by the present invention.

[0048] Symbol explanation:

[0049] 1. PDMS encapsulation layer; 2. Janus WSSe; 3. Terminal block. Detailed Implementation

[0050] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0051] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0052] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0053] Please see Figure 1-13 A method for constructing a highly spin-selective photodetector, comprising:

[0054] Step 1: Select an armchair-shaped lattice of Janus WSSe monolayer material with an asymmetric boundary structure as the basic configuration;

[0055] Step 2: Select the middle region of the basic configuration as the scattering region of the photodetector, and use the armchair-shaped lattice structures at both ends connected to the scattering region as the left and right leads of the photodetector, respectively.

[0056] 1. Crystal structure selection and configuration construction:

[0057] The reason for choosing armchair-type nanoribbons made of Janus WSSe monolayer material as the basic configuration is that this structure has natural lateral asymmetry, which is beneficial for exciting and transmitting spin-polarized photocurrents.

[0058] 2. Definition of the central scattering region:

[0059] A finite length is set in the middle region of the armchair-shaped nanoribbon as a scattering region, typically about 5 to 10 unit cells (depending on the actual simulation scale). This region is used to receive polarized light irradiation, generate photoexcited electrons, and analyze their transport properties.

[0060] 3. Left and right lead wire settings:

[0061] The lead region employs the same Janus WSSe armchair lattice structure as the scattering region, with periodic boundary conditions applied to ensure continuous matching of the structure at the interface. This setup enables semi-infinite extension of the electrodes at both ends of the device, facilitating modeling using the NEGF method.

[0062] Substituting the constructed scattering region and left and right lead wire models into the NEGF framework, the spin-dependent transmission spectrum T is solved. σ (E) and current. The expression for current is as follows:

[0063]

[0064] σ∈{↑,↓} represents the two components of spin up (↑) and spin down (↓), T σ (E) represents the probability that an electron with energy E passes through the device from the left electrode to the right electrode, i.e., the transmission coefficient; f L (E) represents the Fermi-Dirac distribution function of the left electrode, f R (E) represents the Fermi-Dirac distribution function of the right electrode, and I represents the electron filling probability of the left and right electrodes; σ This represents a spin flow from L to R with a spin direction of σ; denoted by Planck's constant, and e represents the electron charge.

[0065] Step 3: Introduce single-atom-level vacancy defects into the scattering region of the photodetector, and perform electronic localization state analysis on the scattering region after defect introduction to obtain the analysis results;

[0066] 1. Defect type selection:

[0067] Introducing single-atom-level vacancy defects in the central scattering region of Janus WSSe armchair-shaped nanoribbons:

[0068] Sulfur vacancies (V) S ): Removal of a single sulfur atom;

[0069] Selenium vacancy (V Se ): Removal of individual selenium atoms;

[0070] Sulfur-selenium exchange defect (Swap) Se-S ): Exchange the positions of a sulfur atom and a selenium atom.

[0071] 2. Defect control mechanism:

[0072] Defects introduce localized states into the band gap, which are more sensitive to photon responses of specific energies, thereby enhancing light absorption.

[0073] The defects disrupt the crystal symmetry, especially the original boundary symmetry of the armchair-shaped nanoribbons, further enhancing the local structural asymmetry, which is conducive to generating highly directional spin-polarized photocurrents.

[0074] 3. Perform electronic local state analysis using first-principles calculations.

[0075] 1. Calculate the density of states (DOS) and partial-wavelength density of states (PDOS) using DFT:

[0076] By calculating the total density of states and the projected density of states of each atomic orbital after the introduction of defects using density functional theory (DFT), the positions and properties of defect-induced electronic localized states can be clearly identified.

[0077] Specifically, the band structure and density of states of Janus WSSe nanoribbons were calculated using first-principles calculations (based on density functional theory, DFT), employing the following Kohn-Sham equations:

[0078]

[0079] Free electron kinetic energy term, Let m represent the reduced Frank constant, and m represent the electron rest mass. V represents the Laplace operator; ext (r) represents the external potential field (including the atomic nucleus and the external electric field); V H (r) represents the average electrostatic repulsion potential energy between electrons; V xc (r) represents the exchange-correlation potential; ψ i (r) represents the i-th single-electron wavefunction (Kohn-Sham orbital) in the Kohn-Sham equation, ε i It represents the intrinsic energy, which determines the energy level position of the electron in that state.

[0080] 2. Local state influence mechanism:

[0081] The enhanced density of d or p orbital states near the defect manifests as band flattening and an increase in the effective electron mass, which helps to form excited state trapping centers. The enhanced local states lead to enhanced electron-photon interactions, increasing the absorption coefficient in specific wavelength regions.

[0082] Step 4: When the analysis results meet the set criteria, a transition metal element is introduced as a substitute atom at the tungsten atom sites of the Janus WSSe nanoribbon structure in the scattering region to form a doping model;

[0083] Step 5: Analyze the stability and band structure of the doping model under different transition metal elements and select transition metal elements that meet the preset conditions as doping elements.

[0084] 1. Doping position setting:

[0085] In the Janus WSSe nanoribbon structure, transition metal elements (such as Ni, Cr, Fe, etc.) are introduced as substitute atoms at tungsten (W) atomic sites to construct a doping model.

[0086] 2. Doping concentration control:

[0087] Typically, a single W atom is replaced in a supercell (with a typical concentration of 3–6%) to ensure that the calculations are reasonable and experimentally feasible.

[0088] II. Calculation Steps and Formula Explanation

[0089] 1. Calculation of doping formation energy

[0090] Used to determine whether doping is thermodynamically stable. The formation energy formula is as follows:

[0091] The formula for calculating the doping formation energy is:

[0092] E form =E doped -E pure +μw-μx

[0093] Among them, E form E represents the doping formation energy. doped E represents the total energy of the doped structure. pure μw represents the total energy of the pure structure, μx represents the chemical potential of the tungsten atom, and μx represents the chemical potential of the dopant element x.

[0094] Judgment criteria:

[0095] If E form <0 indicates that the dopant is thermodynamically stable; multiple elements are compared, and the one with the lowest formation energy is selected as the preferred one.

[0096] 2. Band structure and spin splitting analysis

[0097] The spin-polarized band structure (including SOC) of the doped system was calculated, and the degree of spin splitting in the band structure was evaluated. The formula for calculating the degree of spin splitting is as follows:

[0098] ΔE spin =|E↑-E↓|

[0099] Where E↑ represents the spin-based eigenstate energy, and E↓ represents the spin-based eigenstate energy.

[0100] Judgment criteria:

[0101] Dopant elements with large spin splitting, unclosed band structure, and moderate band gap are selected to ensure that they are conducive to the generation of spin photocurrent.

[0102] The photodetector is reconstructed based on the parameters calculated above, and the steps are as follows:

[0103] 1. Selecting the device lattice type and boundary structure

[0104] Armchair-shaped nanoribbons were constructed using Janus WSSe monolayer material due to its natural asymmetry (S on top and Se on the bottom) and edge state modulation capabilities.

[0105] Using armchair nanoribbons with asymmetric boundary structures as the building block is beneficial for forming direction-dependent spin-polarized currents.

[0106] 2. Divide the device area

[0107] The device structure consists of three parts: the left lead, the central scattering region, and the right lead.

[0108] All three parts are constructed using the same Janus WSSe single-layer material to ensure band continuity and address the issue of interface reactive function mismatch.

[0109] 3. Introduce regulatory factors in the central area.

[0110] The aforementioned control factors are introduced into the central scattering region: defect engineering (such as S vacancies, Se vacancies, S-Se exchanges, etc.); doping engineering (such as W atoms being replaced by Ni). This region is a photosensitive region and also the main location for controlling spin selectivity.

[0111] 4. Construct a transport model and add polarized illumination.

[0112] Using first-principles calculations combined with the non-equilibrium Green's function (NEGF) method, the following simulation conditions were set:

[0113] The incident light is polarized and shines perpendicularly (along the z-axis);

[0114] The current output direction is along the y-axis (nanobelt axis);

[0115] Apply a small range bias voltage V b The photogenerated spin polarization current is measured on the left and right leads. The construction is complete when the current meets the set conditions.

[0116] 5. Achieve a seamless connection structure

[0117] like Figure 13 As shown, the photodetector can be constructed using PDMS packaging. The three parts of the entire device adopt Janus WSSe nanoribbons with consistent structure, avoiding problems such as band misalignment, interface scattering and electron-hole imbalance injection that exist in traditional heterostructures, and ensuring a high-efficiency, low-power, and high-response spin photocurrent output path.

[0118] Step 6: Apply bias voltage control to the doped photodetector to construct a synergistic control strategy, thereby improving the spin selectivity and response intensity of the device and completing the construction of the photodetector.

[0119] Step 6 includes:

[0120] 1. Set unbalanced bias conditions

[0121] Within the first-principles calculation framework and the non-equilibrium Green's function (NEGF), an electrochemical potential difference V is applied to the left and right leads respectively. b (e.g. -V / 2 and +V / 2).

[0122] Changing the bias voltage (e.g., scanning from 0.0V to 0.5V) puts the system in a non-equilibrium state, triggering the migration of photoexcited charge carriers.

[0123] 2. Calculate the photogenerated current and spin polarization.

[0124] After introducing the polarized illumination condition (incident direction along the z-axis), the photocurrent under bias voltage is calculated:

[0125] Calculations using the Landauer-Büttiker formula combined with spin channel division:

[0126]

[0127] Among them, T σ (E,V b ) represents the transmission coefficient under bias voltage, i.e., the probability of passing through the device from the left electrode to the right electrode, reflecting the quantum scattering process. E represents an electron with energy E; f L (E) represents the Fermi-Dirac distribution function of the left electrode, f R (E) represents the Fermi-Dirac distribution function of the right electrode, f L (E)-f R (E) represents the driving force; I σ (V b ) represents a spin flow with a spin component of σ;

[0128] The formula for calculating spin polarizability is:

[0129]

[0130] Where I↑ represents the spin-up light response intensity, and I↓ represents the spin-down light response intensity.

[0131] 3. Scan bias and optimize output window

[0132] By performing a bias scan, the optimal bias window that meets the following requirements is found:

[0133] Photocurrent intensity: I = I↑ + I↓ (maximum);

[0134] Spin polarizability (SPR) is close to ±1 (i.e., a single spin state dominates);

[0135] The system retains its semiconductor properties, avoiding entering the metallic state or unstable region.

[0136] The construction effect of the photodetector of the present invention will be further explained below with reference to the specific accompanying drawings:

[0137] A. The effect of defects on the spin photoelectric effect (SPGE)

[0138] 1. Band structure and density of states (PDOS) of intrinsic WSSe materials

[0139] like Figure 2-5 As shown, to investigate the impact of defects on the photoelectric properties of Janus WSSe materials, this invention calculated its band structure and projected density of states. For intrinsic WSSe materials, its band structure exhibits obvious semiconductor characteristics, with the Fermi level near the top of the valence band, showing slight p-type characteristics. The valence and conduction bands are mainly composed of W d orbitals and S / Se p orbitals. The flat band edges indicate a large effective carrier mass, but the mobility may be low.

[0140] 2. The effect of doping control on band structure

[0141] like Figure 5-6 As shown, this invention further analyzes the effect of transition metal doping on the electronic structure of Janus WSSe, selecting Fe, Co, and Ni atoms to replace W atoms, respectively. The results show that all three doping methods lead to an upward shift of the Fermi level, resulting in an overall n-type conductivity in the material, while spin splitting occurs in the band structure near the Fermi level. Specifically:

[0142] (1) Fe doping introduces a new density of states and significantly enhances spin splitting, exhibiting strong local magnetism and spin polarization;

[0143] (2) Co doping has weaker spin splitting because its d orbital electron configuration is more symmetrical and its magnetic moment is smaller.

[0144] (3) Ni doping exhibits the strongest spin splitting phenomenon, mainly due to Ni having more d electrons and stronger spin orbital coupling, which has a significant exchange effect on conduction band electrons.

[0145] Conclusion: Ni doping is the most effective way to control the spin structure in low-dimensional WSSe structures, making them suitable for constructing photodetectors with high spin selectivity.

[0146] B. Spin photocurrent behavior analysis

[0147] like Figure 8-9 As shown, the relationship between spin-resolved photocurrent and polarization angle and photon energy under different doping conditions was calculated. The results show that:

[0148] (1) The photocurrent of all systems changes with the polarization angle in a cosine function, which is consistent with the characteristics of linear spin photoelectric effect;

[0149] (2) Pure WSSe has a weaker photocurrent intensity and less obvious spin splitting;

[0150] (3) The Ni-doped structure exhibits strong spin-polarized photocurrent in the mid-to-high energy range (2.4–3.8 eV);

[0151] (4) At 3.8 eV, the difference between the spin up and down photocurrents of the Ni-doped system is the largest, indicating that it has excellent polarization sensitivity and selectivity.

[0152] Conclusion: Doping enhances lattice symmetry breaking, thereby improving spin photocurrent splitting, which is a key factor in designing high-response devices.

[0153] C. Spin polarization and extinction ratio analysis

[0154] 1. Spin Polarization Ratio

[0155] like Figure 10 As shown, the Ni-doped system has a spin polarization rate close to 100% at a polarization angle of 90°, which is the highest among all systems, especially at high photon energies (such as 3.8 eV).

[0156] 2. Extinction Ratio

[0157] like Figure 11 As shown, the results of calculating the extinction ratio as a function of photon energy under different doping conditions indicate that:

[0158] (1) The extinction ratio is defined as the ratio of the maximum spin photocurrent intensity under 0° and 90° polarized light;

[0159] (2) At 2.4 eV, the extinction ratio of the spin-down component of the Ni-W system is as high as 47.24;

[0160] (3) At 3.6 eV, the number of Se vacancies (V) Se The defect-induced spin-down component extinction ratio is as high as 947.67, far exceeding that of other structures.

[0161] Conclusion: A high extinction ratio means that the material is sensitive to polarized light and is suitable for high-contrast detection scenarios, such as optical communication and quantum readout.

[0162] D. Bias control effect

[0163] like Figure 12 As shown, an external bias voltage can effectively increase the photocurrent intensity and modulate the spin-resolved response:

[0164] (1) At low photon energy (1.8eV), applying a bias voltage can significantly increase the spin-up component photocurrent and suppress the spin-down response;

[0165] (2) At high photon energies (3.4 eV, 3.8 eV), the bias voltage further enhances the existing spin polarization splitting;

[0166] (3) The Ni-W device, under a bias voltage of 1.0V, exhibits a spin-down component photocurrent of up to 4.6 (unit: a0). 2 / photon), far exceeding other structures.

[0167] Conclusion: This demonstrates that the combined use of bias and doping strategies can achieve optically and electrically controlled spin current regulation, providing a theoretical basis for constructing practical devices.

[0168] The present invention also provides a system for constructing a highly spin-selective photodetector, comprising:

[0169] The basic configuration determination module is used to select an armchair-shaped lattice with an asymmetric boundary structure as the basic configuration in the nanoribbon structure of Janus WSSe monolayer material;

[0170] A preliminary construction module for a photodetector is used to select the middle region of the basic configuration as the scattering region of the photodetector, and the armchair-shaped lattice structures at both ends connected to the scattering region are used as the left and right leads of the photodetector, respectively.

[0171] The electronic localized state analysis module is used to introduce single-atom-level vacancy defects into the scattering region of a photodetector and perform electronic localized state analysis on the scattering region after the defect is introduced to obtain the analysis results.

[0172] The impurity doping module is used to introduce transition metal elements as substitute atoms into the tungsten atom sites of the Janus WSSe nanobelt structure in the scattering region to form a doping model when the analysis results meet the set standards.

[0173] The doping element determination module is used to analyze the stability and band structure of the doping model under different transition metal elements and select transition metal elements that meet the preset conditions as doping elements.

[0174] The bias control module is used to control the bias of the photodetector after doping with elements to construct a synergistic control strategy.

[0175] Compared with the prior art, the beneficial effects of the high spin-selectivity photodetector construction system provided by the present invention are the same as the beneficial effects of the high spin-selectivity photodetector construction method described in the above technical solution, and will not be repeated here.

[0176] The present invention also provides an electronic device, including a bus, a transceiver, a memory, a processor, and a computer program stored in the memory and executable on the processor. The transceiver, the memory, and the processor are connected via the bus. The computer program, when executed by the processor, implements the steps in the above-described method for constructing a high spin-selective photodetector. Compared with the prior art, the beneficial effects of the electronic device provided by the present invention are the same as those of the method for constructing a high spin-selective photodetector described above, and will not be elaborated upon here.

[0177] The present invention also provides a computer-readable storage medium having a computer program stored thereon, characterized in that, when the computer program is executed by a processor, it implements the steps in the above-described method for constructing a high spin-selective photodetector. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided by the present invention are the same as the beneficial effects of the method for constructing a high spin-selective photodetector described in the above-described technical solution, and will not be repeated here.

[0178] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for constructing a highly spin-selective photodetector, characterized in that, Includes the following steps: Step 1: Select an armchair-shaped lattice of Janus WSSe monolayer material with asymmetric boundary structure as the basic configuration; Step 2: Select the middle region of the basic configuration as the scattering region of the photodetector, and use the armchair-shaped lattice structures at both ends connected to the scattering region as the left and right leads of the photodetector, respectively. Step 3: Introduce single-atom-level vacancy defects into the scattering region of the photodetector, and perform electronic localization state analysis on the scattering region after defect introduction to obtain the analysis results; Step 4: When the analysis results meet the set criteria, a transition metal element is introduced as a substitute atom at the tungsten atom sites of the Janus WSSe nanoribbon structure in the scattering region to form a doping model; Step 5: Analyze the stability and band structure of the doping model under different transition metal elements and select transition metal elements that meet the preset conditions as doping elements. Step 6: Implement a bias control strategy for the doped photodetector.

2. The method for constructing a highly spin-selective photodetector according to claim 1, characterized in that, In step 3, the single-atom-level vacancy defects include: sulfur vacancies, selenium vacancies, and sulfur-selenium exchange defects.

3. The method for constructing a highly spin-selective photodetector according to claim 1, characterized in that, Also includes: In step 3, the total density of states and the projected density of states of each atomic orbital in the scattering region after the defect is introduced are calculated using density functional theory to complete the analysis of the electronic localized states of the scattering region.

4. The method for constructing a highly spin-selective photodetector according to claim 1, characterized in that, Step 5 includes: Calculate the doping formation energy of the doping model under different transition metal elements to determine the thermodynamic stability of the doped metal element; The spin-polarized band structure of the doped model was calculated, and the degree of spin splitting in the band was evaluated. When the thermodynamic stability and spin splitting degree of the doped metal element meet the preset conditions, the corresponding metal element is used as the doping element.

5. The method for constructing a highly spin-selective photodetector according to claim 4, characterized in that, The formula for calculating the doping formation energy is: A form =E doped -A pure +µw-µx Among them, E form E represents the doping formation energy. doped E represents the total energy of the doped structure. pure μw represents the total energy of the pure structure, μx represents the chemical potential of the tungsten atom, and μx represents the chemical potential of the dopant element x.

6. A system for constructing a highly spin-selective photodetector, characterized in that, include: The basic configuration determination module selects the armchair-shaped lattice of Janus WSSe monolayer material with asymmetric boundary structure as the basic configuration. A preliminary construction module for a photodetector is used to select the middle region of the basic configuration as the scattering region of the photodetector, and the armchair-shaped lattice structures at both ends connected to the scattering region are used as the left and right leads of the photodetector, respectively. The electronic localized state analysis module is used to introduce single-atom-level vacancy defects into the scattering region of a photodetector and perform electronic localized state analysis on the scattering region after the defect is introduced to obtain the analysis results. The impurity doping module is used to introduce transition metal elements as substitute atoms into the tungsten atom sites of the Janus WSSe nanobelt structure in the scattering region to form a doping model when the analysis results meet the set standards. The doping element determination module is used to analyze the stability and band structure of the doping model under different transition metal elements and select transition metal elements that meet the preset conditions as doping elements. The bias control module is used to control the bias of the photodetector after doping with elements to construct a synergistic control strategy.

7. An electronic device comprising a bus, a transceiver, a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the transceiver, the memory, and the processor are connected via the bus, characterized in that, When the computer program is executed by the processor, it implements the steps in the method for constructing a high spin-selective photodetector as described in any one of claims 1-5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps in the method for constructing a high spin-selective photodetector as described in any one of claims 1-5.

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