LiInSe2 medium-wave infrared photoelectric material optimization method and device and target doping structure crystal

Abstract

The invention provides a LiInSe2 medium-wave infrared photoelectric material optimization method and device and a target doped structure crystal, the method comprises the following steps: determining a plurality of doping positions in a LiInSe2 crystal based on a rule of crystal symmetry and spatial distribution uniformity of doped elements, each doping position comprising the position of a part of In atoms in the LiInSe2 crystal; metal atoms with valence electron structures similar to In atoms are doped into the LiInSe2 crystal according to the multiple doping positions so as to replace part of In atoms in the LiInSe2 crystal, and multiple doped structure crystals are obtained; and determining a plurality of target doped structure crystals based on the plurality of doped structure crystals by adopting a first principle and a multi-layer screening mode, and taking the plurality of target doped structure crystals as the optimized medium-wave infrared photoelectric material. According to the invention, fine regulation and control of an energy band structure and photoelectric response can be realized, the stability of the medium-wave infrared photoelectric material is improved, and the absorption performance of medium-wave infrared light is remarkably enhanced.

Description

Technical Field

[0001] This invention relates to the field of infrared optoelectronic materials technology, and in particular to a method, apparatus and target doped structure crystal for optimizing LiInSe2 mid-wave infrared optoelectronic materials. Background Technology

[0002] Infrared detectors, as core optoelectronic devices, are widely used in military, medical, and environmental monitoring fields. Currently, mainstream infrared detectors can be divided into two main categories: cooled (InSb, HgCdTe, T2SL) infrared detectors and uncooled (vanadium oxide, amorphous silicon) infrared detectors. Different types of detectors have different performance limitations. While InSb-based detectors have a mature application foundation, their narrow bandgap, non-tunable wavelength, and low operating temperature make them unsuitable for engineering applications. MCT (HgCdTe) detectors use HgCdTe material, which suffers from poor uniformity, interface instability, and complex epitaxial growth and subsequent processing. Type-II superlattice (T2SL) detectors have advantages such as tunable bandgap, low Auger recombination rate, high effective electron mass, and good material uniformity, but their actual device performance has not yet reached theoretical expectations. Uncooled infrared detectors, while possessing advantages such as low price, small size, and light weight, making them widely applicable in scenarios with less demanding performance requirements, are inferior to cooled detectors in terms of sensitivity, noise level, and detection range.

[0003] Traditional infrared optoelectronic materials (InSb, HgCdTe, T2SL, etc.) often suffer from low absorption efficiency, limited absorption range, and insufficient absorption intensity in the mid-wave infrared (MWIR, 3–5 μm) band, making it difficult to meet the comprehensive performance requirements of high-performance mid-wave infrared detectors. Especially in practical applications, mid-wave infrared detectors typically require materials with suitable bandgap (0.1–0.8 eV) tuning capability, good light absorption, high carrier mobility, low effective mass, and good material structural stability and process compatibility. The traditional infrared optoelectronic materials mentioned above cannot meet these practical application requirements. Therefore, there is an urgent need to develop a novel infrared optoelectronic material with tunable bandgap, excellent absorption performance, and good stability.

[0004] LiInSe2 compounds exhibit excellent optical absorption properties due to their unique electronic, thermal, and structural characteristics. LiInSe2 crystals, with their high transmittance in the near-infrared region, wide transparency range, sufficiently large birefringence, high laser damage threshold, and low two-photon absorption coefficient, have become a promising candidate material for infrared detection. However, the unstable electronic structure and limitations in optical properties of LiInSe2 crystals hinder their further application in infrared optoelectronic devices, and the difficulty in obtaining In limits their large-scale production. Nevertheless, the LiInSe2 compound system can still be explored through different approaches. Summary of the Invention

[0005] In view of this, embodiments of the present invention provide a method, apparatus and target doped structure crystal for optimizing LiInSe2 mid-wave infrared optoelectronic materials, in order to eliminate or improve one or more defects existing in the prior art.

[0006] One aspect of the present invention provides a method for optimizing LiInSe2 mid-wave infrared optoelectronic materials, the method comprising the following steps: Multiple doping sites in the LiInSe2 crystal are determined based on the rules of crystal symmetry and the spatial distribution uniformity of doping elements. Each doping site includes the location of a portion of the In atoms in the LiInSe2 crystal. Metal atoms with similar valence electron structures to In atoms are doped into LiInSe2 crystals at the aforementioned multiple doping sites to replace some of the In atoms in the LiInSe2 crystals, thereby obtaining multiple doped crystal structures. Using first-principles calculations and multi-layer screening, multiple target doped crystal structures are determined based on the aforementioned multiple doped crystal structures, and these multiple target doped crystal structures are used as optimized mid-wave infrared optoelectronic materials.

[0007] In some embodiments of the present invention, the step of determining multiple target doped crystal structures based on the multiple doped crystal structures using first-principles calculations and multi-layer screening includes: The formation energy, band gap, light absorption coefficient, effective electron mass, and effective hole mass of each doped crystal structure are calculated using first-principles calculations based on the spatial position information of each doped crystal structure and the number and spatial position information of each type of atom in each doped crystal structure. A plurality of first-doped structure crystals are determined based on the plurality of doped structure crystals using a first-layer screening criterion, wherein the first-layer screening criterion includes a formation energy of less than a first threshold. A second-layer screening criterion is used to determine a plurality of second-doped crystals based on the plurality of first-doped crystals. The second-layer screening criterion includes a band gap greater than a second threshold and less than a third threshold, wherein the third threshold is greater than the second threshold. A third-layer screening criterion is used to determine a plurality of third-doped crystals based on the plurality of second-doped crystal structures. The third-layer screening criterion includes an optical absorption coefficient greater than a fourth threshold. A fourth-layer screening criterion is used to determine a plurality of fourth-layer doped structure crystals based on the plurality of third-layer doped structure crystals, and each fourth-layer doped structure crystal is used as a target doped structure crystal. The fourth-layer screening criterion includes that the effective electron mass and the effective hole mass are less than a fifth threshold.

[0008] In some embodiments of the present invention, the formula for calculating the formation energy is: E form =E droped -E pristine +E M -E x Among them, E droped E represents the total energy of a doped crystal structure. pristine E represents the total energy of a LiInSe2 crystal. M E represents the total energy of the doped metal atoms in the reference state. x This represents the total energy of the replaced In atom in the reference state.

[0009] In some embodiments of the present invention, the first threshold is 0.7 eV, the second threshold is 0.25 eV, the third threshold is 1.05 eV, and the fourth threshold is 10 eV. 4 cm -1 The fifth threshold is 1.

[0010] In some embodiments of the present invention, the spatial position information of the doped crystal structure includes the length, width, and height of the doped crystal structure, as well as the angles of the horizontal, vertical, and axial axes in a spatial rectangular coordinate system; the spatial position information of the atoms includes the horizontal, vertical, and axial coordinates of the atoms in a spatial rectangular coordinate system.

[0011] In some embodiments of the present invention, the doping concentration of metal atoms varies depending on the spatial structure of the LiInSe2 crystal.

[0012] In some embodiments of the present invention, the spatial structure of the LiInSe2 crystal includes the I41 / amd space group and the R3m space group. When the spatial structure of the LiInSe2 crystal is the I41 / amd space group, the doping concentration of metal atoms is 50%. When the spatial structure of the LiInSe2 crystal is the R3m space group, the doping concentration of metal atoms is 1 / 3 or 2 / 3.

[0013] In some embodiments of the present invention, the metal atoms include Ga atoms, Al atoms, Sn atoms and Sb atoms.

[0014] In some embodiments of the present invention, the plurality of target doped structure crystals include LiIn with an I41 / amd space group structure formed by Al atom doping. 1 / 2 Al 1 / 2 Se2 crystals and LiIn with R3m space group structure formed by Sb atom doping. 2 / 3 Sb 1 / 3 Se2 crystals and LiIn 1 / 3 Sb 2 / 3 Se2 crystal.

[0015] Another aspect of the present invention provides a target doped structure crystal, which is obtained by the LiInSe2 mid-wave infrared optoelectronic material optimization method described above, wherein the target doped structure crystal is LiIn 1-x M x Se2 crystal, where M represents the doped metal atoms and x represents the doping concentration of the metal atoms.

[0016] Another aspect of the present invention provides a LiInSe2 mid-wave infrared optoelectronic material optimization device, the device comprising: a computer device including a processor and a memory, the memory storing computer instructions, the processor executing the computer instructions stored in the memory, and the device implementing the steps of the aforementioned method when the computer instructions are executed by the processor.

[0017] Another aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the aforementioned method.

[0018] Another aspect of the present invention provides a computer program product including computer instructions that, when executed by a processor, implement the steps of the aforementioned method.

[0019] The LiInSe2 mid-wave infrared optoelectronic material optimization method, device, and target doped structure crystal of the present invention optimize the LiInSe2 mid-wave infrared optoelectronic material, thereby achieving fine control of the band structure and photoelectric response, improving the stability of the material, and significantly enhancing the mid-wave infrared light absorption performance. This not only breaks through the bottlenecks of traditional infrared optoelectronic materials in terms of bandgap control, device stability, and photoelectric performance, but also broadens the application scope and application scenarios.

[0020] Additional advantages, objects, and features of the present invention will be set forth in part in the following description and will become apparent to those skilled in the art upon examination of the following or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and obtained by the structures particularly pointed out in the description and drawings.

[0021] Those skilled in the art will understand that the purposes and advantages that can be achieved by the present invention are not limited to the above specific descriptions, and the above and other purposes that can be achieved by the present invention will be more clearly understood based on the following detailed description. Attached Figure Description

[0022] The accompanying drawings, which are provided to further illustrate the invention and form part of this application, are not intended to limit the scope of the invention.

[0023] Figure 1 This is a flowchart illustrating the optimization method for LiInSe2 mid-wave infrared optoelectronic materials in one embodiment of the present invention. Figure 2 This is a schematic diagram of the structure of a LiInSe2 crystal with space group I41 / amd in one embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of a LiInSe2 crystal with space group R3m in one embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of a doped crystal with an I41 / amd space group formed by Al atom doping in one embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of a doped crystal with an R3m space group formed by Sb atom doping in one embodiment of the present invention; Figure 6 This is a schematic diagram of the absorption spectra of a LiInSe2 crystal and a doped crystal with an I41 / amd space group structure formed by Al atom doping in one embodiment of the present invention. Figure 7 This is a schematic diagram of the absorption spectra of a LiInSe2 crystal and a doped crystal with an R3m space group structure formed by Sb atom doping, according to an embodiment of the present invention. Detailed Implementation

[0024] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments and the accompanying drawings. Here, the exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0025] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, the accompanying drawings only show structures and / or processing steps closely related to the solutions according to the present invention, while other details that are not closely related to the present invention are omitted.

[0026] It should be emphasized that the term "include / comprises" when used herein refers to the existence of features, elements, steps or components, but does not exclude the existence or addition of one or more other features, elements, steps or components.

[0027] It should also be noted that, unless otherwise specified, the term "connection" herein may refer not only to a direct connection but also to an indirect connection involving an intermediate.

[0028] In the following description, embodiments of the invention will be illustrated with reference to the accompanying drawings. In the drawings, the same reference numerals represent the same or similar parts, or the same or similar steps.

[0029] To explore a novel infrared optoelectronic material with excellent photoelectric properties and broaden the application range and scenarios of LiInSe2 crystals in infrared optoelectronic devices, and to overcome the bottlenecks of traditional infrared optoelectronic materials in terms of bandgap control, device stability, and photoelectric performance, this invention provides an optimization method, device, and target doped crystal structure for LiInSe2 mid-wave infrared optoelectronic materials. This achieves precise control of the band structure and photoelectric response, improves the stability of mid-wave infrared optoelectronic materials, and significantly enhances mid-wave infrared light absorption performance. It can be applied to various optoelectronic fields such as infrared detectors, photoelectric conversion devices, and photovoltaic devices, meeting the requirements of these devices for sensitivity, response range, and stability, thus broadening the application range and scenarios.

[0030] Figure 1 This is a schematic flowchart illustrating the optimization method for LiInSe2 mid-wave infrared optoelectronic materials in one embodiment of the present invention. Figure 1 As shown, the method includes the following steps: Step S110: Based on the rules of crystal symmetry and the spatial distribution uniformity of doped elements, multiple doping sites in the LiInSe2 crystal are determined, wherein each doping site includes the location of a portion of the In atoms in the LiInSe2 crystal.

[0031] Due to its excellent optical transparency, wide transmission window, high laser damage threshold, and strong nonlinear optical effects, LiInSe2 crystal is suitable for mid-wave infrared detection. This method selects LiInSe2 crystal as the base material and optimizes it to expand the range of novel LiInSe2 compound crystal materials with excellent optoelectronic properties. The structure of the LiInSe2 crystal can be determined by its spatial position information, including the length (a), width (b), and height (c), as well as the angles of the horizontal, vertical, and axial axes in a Cartesian coordinate system. The spatial position information of the atoms includes their horizontal, vertical, and axial coordinates. In other words, this information can be used as input to this step to output multiple possible doping sites in the LiInSe2 crystal. Studies on the optoelectronic properties of LiInSe2 crystal materials typically focus on the I41 / amd and R3m space groups because these two space groups are more stable and easier to manipulate under normal conditions. The LiInSe2 crystal structures with space groups I41 / amd and R3m can be respectively as follows: Figure 2 and Figure 3 The crystal structure shown. Determining possible doping sites based on crystal symmetry and the rules governing the spatial uniformity of dopant element distribution ensures a uniform distribution of doped metal atoms while preserving crystal structure symmetry as much as possible. The determined possible doping sites can include, for example... Figure 4 The positions of the individual Al atoms shown may also include, for example: Figure 5 The positions of each Sb atom are shown in the diagram.

[0032] In step S120, metal atoms with similar valence electron structures to In atoms are doped into the LiInSe2 crystal at the multiple doping positions to replace some of the In atoms in the LiInSe2 crystal, and multiple doped crystal structures are obtained.

[0033] Specifically, metal atoms with similar valence electron structures to In atoms include Ga, Al, Sn, and Sb atoms. In this step, Ga, Al, Sn, and Sb atoms are used to replace In atoms at multiple possible doping sites determined in step S110, thereby changing the In atom content in the LiInSe2 crystal structure and obtaining multiple possible doped crystal structures corresponding to the above four atom doping methods. 1-x M xSe2, where M represents the doped metal atom and x represents the doping concentration or doping ratio of the metal atom. Choosing metal atoms with similar valence electron structures to In atoms to replace In atoms in LiInSe2 crystals is beneficial for maintaining crystal structure stability and broadening the applications of the crystal material. Specifically, doping with Ga and Al atoms can improve structural stability and photoelectric conversion effect, while doping with Sb atoms can further broaden the infrared transmission range and enhance nonlinear response. Sn atoms can control the carrier concentration, thereby obtaining new photoelectric properties. This results in LiInSe2-based doped crystals exhibiting good carrier mobility, achieving highly efficient photoelectric conversion.

[0034] Step S130: Using first-principles calculations and multi-layer screening, multiple target doped crystal structures are determined based on the multiple doped crystal structures, and the multiple target doped crystal structures are used as the optimized mid-wave infrared optoelectronic material.

[0035] In some embodiments, step S130, which involves determining multiple target doped crystal structures based on the multiple doped crystal structures using first-principles and multi-layer screening methods, includes the following steps: The formation energy, band gap, light absorption coefficient, effective electron mass, and effective hole mass of each doped crystal structure are calculated using first-principles calculations based on the spatial position information of each doped crystal structure and the number and spatial position information of each type of atom in each doped crystal structure. A plurality of first-doped structure crystals are determined based on the plurality of doped structure crystals using a first-layer screening criterion, wherein the first-layer screening criterion includes a formation energy of less than a first threshold. A second-layer screening criterion is used to determine a plurality of second-doped crystals based on the plurality of first-doped crystals. The second-layer screening criterion includes a band gap greater than a second threshold and less than a third threshold, wherein the third threshold is greater than the second threshold. A third-layer screening criterion is used to determine a plurality of third-doped crystals based on the plurality of second-doped crystal structures. The third-layer screening criterion includes an optical absorption coefficient greater than a fourth threshold. A fourth-layer screening criterion is used to determine a plurality of fourth-layer doped structure crystals based on the plurality of third-layer doped structure crystals, and each fourth-layer doped structure crystal is used as a target doped structure crystal. The fourth-layer screening criterion includes that the effective electron mass and the effective hole mass are less than a fifth threshold.

[0036] In the above steps, the spatial position information of the doped crystal structure includes the length a, width b, and height c of the doped crystal structure, as well as the angles of the horizontal, vertical, and triangular axes in a spatial rectangular coordinate system; the spatial position information of the atoms includes the horizontal, vertical, and triangular coordinates of the atoms in a spatial rectangular coordinate system.

[0037] To screen for high-performance mid-wave infrared optoelectronic materials, this embodiment uses first-principles calculations to determine the formation energy, band gap, light absorption coefficient, effective electron mass, and effective hole mass of multiple possible doped crystal structures. A multi-layer screening strategy is then employed to select the key structure from these potential doped crystal structures. In the specific implementation, the first threshold can be set to 0.7 eV, the second threshold to 0.25 eV, the third threshold to 1.05 eV, and the fourth threshold to 10 eV. 4 cm -1 The fifth threshold can be set to 1. Specifically, by using a first-layer screening criterion with a band gap less than 0.7 eV, stable crystalline materials can be screened out; by using a second-layer screening criterion with a band gap greater than 0.25 eV and less than 1.05 eV, crystal structures with suitable band gap sizes and precise band gap control can be identified, facilitating subsequent mid-wavelength property studies; to identify materials with strong light absorption capabilities, a third-layer screening criterion is used to select materials with multiple light absorption coefficients greater than 10. 4 cm -1 The crystal structures were screened out; finally, based on the calculated effective carrier mass, the crystal structures with low effective carrier mass (both electron and hole effective masses are less than 1) were screened out using the fourth screening criterion, thus obtaining the optimized mid-wave infrared optoelectronic material.

[0038] In a specific implementation, the formula for calculating the formation energy can be expressed as: E form =E droped -E pristine +E M -E x Among them, E droped E represents the total energy of a doped crystal structure. pristine E represents the total energy of the undoped, pristine LiInSe2 crystal. M E represents the total energy of the doped metal atoms (Ga, Al, Sn, or Sb atoms) in the reference state. x This represents the total energy of the substituted atom (In atom) in the reference state. The magnitude of the formation energy reflects the stability of the doped structure; a smaller formation energy indicates higher stability.

[0039] In some embodiments, the doping concentration of metal atoms varies depending on the spatial structure of the LiInSe2 crystal.

[0040] Furthermore, the spatial structure of the LiInSe2 crystal includes the I41 / amd space group and the R3m space group. When the spatial structure of the LiInSe2 crystal is the I41 / amd space group, the doping concentration or doping ratio of the metal atoms is 50% (1 / 2), and the corresponding doped crystal structure obtained is LiIn. 1 / 2 M 1 / 2 Se2 crystal; when the space structure of the LiInSe2 crystal is R3m space group, the doping concentration or doping ratio of the metal atoms is 1 / 3 or 2 / 3, and the corresponding doped crystal structure obtained is LiIn. 2 / 3 M 1 / 3 Se2 crystals or LiIn 1 / 3 M 2 / 3 Se2 crystal.

[0041] Finally, the photoelectric properties of the optimized mid-wave infrared optoelectronic materials obtained by this method, namely, the multi-target doped crystal structures, were analyzed and verified. By doping with different metal atoms such as Ga, Al, Sn, and Sb, the electronic structure of the LiInSe2 mid-wave infrared optoelectronic material can be significantly altered and its optical performance improved. Ultimately, the LiInSe2 material with the I41 / amd space group structure formed by Al atom doping was determined to be the optimal material. 1 / 2 Al 1 / 2 Se2-doped crystals and LiIn-doped crystals with an R3m space group structure formed by Sb atom doping. 2 / 3 Sb 1 / 3 Se2 and LiIn 1 / 3 Sb 2 / 3 Se2 is the preferred target doped crystal structure and the optimized mid-wave infrared optoelectronic material, such as Figure 4 and Figure 5 As shown.

[0042] Specifically, the formation energy of the doped crystal with the I41 / amd space group structure formed by Al atom doping is reduced to -1.205 eV, improving structural stability; the band gap increases from 0.4638 eV in the intrinsic state (LiInSe2 crystal with I41 / amd space group structure) to 0.6767 eV; and the light absorption capability in the low-energy range of 0.1–0.8 eV is enhanced, making it suitable for broadband optoelectronic devices. After doping with Al atoms, Al… 3+ The 3p orbitals of Al atoms introduce less density of states near the conduction band bottom, causing the conduction band bottom (CBM) to shift upward and the density of states near the Fermi level to decrease. The band gap of the doped crystal with the R3m space group structure formed by Al atom doping increases from 0.82 eV in the intrinsic state (LiInSe2 crystal with R3m space group structure) to 1.08 eV; the formation energy is -0.99384 eV; due to the weak hybridization of the 3p orbitals of Al atoms, there are fewer new states at the conduction band bottom.

[0043] The formation energy of Ga-doped crystals with the I41 / amd space group structure is relatively high (+0.6 eV). However, the strong hybridization of the 4p orbitals of Ga atoms at the bottom of the conduction band reduces the band gap from 0.46 eV in the intrinsic state (LiInSe2 crystal with I41 / amd space group structure) to 0.36 eV, and enhances the conduction band density of states, which is beneficial for electronic transitions and improves conductivity and infrared sensitivity. The band gap of Ga-doped crystals with the R3m space group structure increases from 0.82 eV in the intrinsic state (LiInSe2 crystal with R3m space group structure) to 1.08 eV. The enhanced hybridization of the 4p orbitals of Ga and Se atoms increases the density of states near the Fermi level, reducing the energy required for electronic excitation. Ga-doped structures possess superior effective carrier mass and good charge transport properties, which can improve infrared absorption performance and photoelectric conversion efficiency.

[0044] The band gap of the Sb-doped crystal with an R3m space group structure was reduced from 0.8283 eV in the intrinsic state (LiInSe2 crystal with R3m space group structure) and tuned to 0.38–0.52 eV, which is closer to the mid-infrared response. Furthermore, it significantly enhanced light absorption in the 1.65–3.00 eV band, especially with the absorption peaks in the x and y axes blue-shifting from 1.6 eV to 1.8 eV, while the light absorption coefficient in the z direction also showed a significant increase. The 5p orbital of the Sb atom introduced new impurity states and intermediate energy levels, significantly altering the valence band top. The density of states distribution in the valence band gap (VBM) and the bottom of the conduction band enhances carrier mobility and directional selectivity, making it suitable for high-performance mid-wave infrared detection scenarios. The strong hybridization of the 5p orbitals of Sb atoms and the 4p orbitals of Se atoms enhances the top of the valence band, while the bottom of the conduction band in some structures also shifts slightly downward. This bidirectional bandgap compression behavior is beneficial for low-energy light absorption. Furthermore, the 5p orbitals of Sb atoms introduce additional electronic states near the bottom of the conduction band and the top of the valence band, resulting in more branches in the band structure and an increase in the density of states, which is beneficial for enhancing the probability of electronic transitions and improving the optical response intensity of the material.

[0045] Regarding formation energy, in the I41 / amd space group structure, Al doping effectively reduces the formation energy, thus making the structure more stable and easier to synthesize under conventional conditions, while Sn, Ga, and Sb doping lead to an increase in formation energy. In the R3m space group, Al doping has a negative formation energy and is the most stable, followed by Sb doping, while Ga doping has a positive but still relatively low formation energy. Regarding band gap, in the I41 / amd space group structure, the intrinsic band gap is small. Al doping increases the band gap, indicating that Al doping makes the crystal structure more stable, but it also raises the light absorption energy level, leading to an increase in the laser energy required for electron transitions. Ga and Sb doping significantly reduce the band gap, improving carrier transport characteristics and exhibiting better light absorption performance in the mid-infrared region. Sn doping makes the band gap negative, altering the semiconductor properties of the material. In the R3m space group structure, Sb doping reduces the band gap, which can optimize photoelectric conversion performance. In terms of optical absorption performance, Al doping in the I41 / amd space group enhances the light absorption capacity of the crystal in the range of 0.1 to 0.8 eV; Sb doping in the R3m space group significantly enhances the light absorption capacity of the crystal in the range of 1.65 to 3 eV, thereby broadening the spectral response range of LiInSe2 materials.

[0046] according to Figure 6 and Figure 7 The results in the absorption spectra shown indicate significant differences in the position and intensity of the light absorption peaks before and after doping along different crystal orientations (x, y, and z axes). Figure 6 As shown (the red, green, and blue lines represent the light absorption intensity along the x, y, and z axes, respectively; the solid and dashed lines represent the light absorption intensity distribution curves of the LiInSe2 crystal and the Al-doped crystal, respectively), after Al doping, the 1.5 eV absorption peak of the I41 / amd space group in the x and y axes red-shifts to 0.9 eV, while the 2.5 eV peak in the z-axis direction blue-shifts to 3.0 eV. Figure 7 As shown (the red, green, and blue lines represent the light absorption intensity along the x, y, and z axes, respectively; the solid and dashed lines represent the light absorption intensity distribution curves of LiInSe2 crystal and the Sb-doped crystal, respectively), after Sb doping, the main absorption peaks of the R3m space group in the x and y axes shifted from 1.6 eV to 1.8 eV, while the original absorption response in the z-axis direction was weakened. This indicates that doping not only alters the electronic structure but also introduces spatial orientation sensitivity into the absorption spectrum, enabling the optimized material to perform applications such as polarization selection or anisotropic detection.

[0047] like Figure 6 As shown, after Al doping, the light absorption coefficient in the low-energy region (0.1–0.8 eV) increases from approximately 1 × 10⁻⁶ eV to approximately 1 × 10⁻⁶ eV. 3 cm -1 Increased to nearly 2×103 cm -1 This indicates that the absorption capacity of the doped structure is significantly enhanced in the infrared region. Simultaneously, the band gap widens from approximately 0.46 eV to 0.67 eV, exhibiting a strong band gap broadening effect. This phenomenon is due to the Al... 3+ The 3p orbital introduces hybrid states near the bottom of the conduction band, which increases the density of states in the conduction band and causes the Fermi level to move closer to the conduction band, thereby lowering the excitation energy threshold and enhancing the probability of low-energy transitions, thus improving the mid-wave infrared absorption performance.

[0048] like Figure 7 As shown, after Sb doping, the absorption intensity in the 1.65–3.00 eV band is significantly improved, the absorption peak is blue-shifted to about 1.8 eV, and the optical absorption coefficient increases to 4 × 10⁻⁶. 5 ~6×10 5 cm -1 It is significantly superior to the intrinsic structure of LiInSe2 crystal with a density of 3×10⁻⁶. 5 cm -1 This is mainly due to the strong hybridization of the 5p and 5s orbitals of Sb with the 4p orbital of Se, which significantly alters the electron distribution at the bottom of the conduction band and the top of the valence band, forming new impurity states or intermediate bands, and leading to band broadening and band gap contraction (from 0.8283 eV to 0.38–0.52 eV). This redistribution of the density of states not only increases the transition probability but also enhances the material's absorption capacity in the z-direction, making it suitable for high-sensitivity detectors in the mid-infrared band.

[0049] The present invention also provides a target doped structure crystal, which is obtained by the LiInSe2 mid-wave infrared optoelectronic material optimization method as described in any of the foregoing embodiments, wherein the target doped structure crystal is LiIn 1- x M x Se2 crystal, where M represents the doped metal atoms and x represents the doping concentration of the metal atoms.

[0050] Corresponding to the above method, the present invention also provides a LiInSe2 mid-wave infrared optoelectronic material optimization device, which includes a computer device, the computer device including a processor and a memory, the memory storing computer instructions, the processor being used to execute the computer instructions stored in the memory, and when the computer instructions are executed by the processor, the device implements the steps of the aforementioned method.

[0051] This invention also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the aforementioned method. The computer-readable storage medium may be a tangible storage medium, such as random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, register, floppy disk, hard disk, removable storage disk, CD-ROM, or any other form of storage medium known in the art.

[0052] This invention also provides a computer program product, including computer instructions that, when executed by a processor, implement the steps of the aforementioned method.

[0053] It should be understood by those skilled in the art that the various exemplary components, systems and methods described in conjunction with the embodiments disclosed herein can be implemented in hardware, software or a combination of the two. Whether it is specifically performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present invention are programs or code segments that are used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link via a data signal carried in a carrier.

[0054] It should be understood that the present invention is not limited to the specific configurations and processes described above and illustrated in the figures. For the sake of brevity, a detailed description of known methods is omitted. In the above embodiments, several specific steps are described and illustrated as examples. However, the method of the present invention is not limited to the specific steps described and illustrated. Those skilled in the art may make various changes, modifications, and additions, or change the order of the steps after understanding the spirit of the present invention.

[0055] In the present invention, features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with or replace features of other embodiments.

[0056] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for optimizing LiInSe2 mid-wave infrared optoelectronic materials, characterized in that, The method includes: Multiple doping sites in the LiInSe2 crystal are determined based on the rules of crystal symmetry and the spatial distribution uniformity of doping elements. Each doping site includes the location of a portion of the In atoms in the LiInSe2 crystal. Metal atoms with similar valence electron structures to In atoms are doped into LiInSe2 crystals at the aforementioned multiple doping sites to replace some of the In atoms in the LiInSe2 crystals, thereby obtaining multiple doped crystal structures. Using first-principles calculations and multi-layer screening, multiple target doped crystal structures are determined based on the aforementioned multiple doped crystal structures, and these multiple target doped crystal structures are used as optimized mid-wave infrared optoelectronic materials.

2. The method according to claim 1, characterized in that, The method of determining multiple target doped crystal structures based on the multiple doped crystal structures using first-principles calculations and multi-layer screening includes: The formation energy, band gap, light absorption coefficient, effective electron mass, and effective hole mass of each doped crystal structure are calculated using first-principles calculations based on the spatial position information of each doped crystal structure and the number and spatial position information of each type of atom in each doped crystal structure. A plurality of first-doped structure crystals are determined based on the plurality of doped structure crystals using a first-layer screening criterion, wherein the first-layer screening criterion includes a formation energy of less than a first threshold. A second-layer screening criterion is used to determine a plurality of second-doped crystals based on the plurality of first-doped crystals. The second-layer screening criterion includes a band gap greater than a second threshold and less than a third threshold, wherein the third threshold is greater than the second threshold. A third-layer screening criterion is used to determine a plurality of third-doped crystals based on the plurality of second-doped crystal structures. The third-layer screening criterion includes an optical absorption coefficient greater than a fourth threshold. A fourth-layer screening criterion is used to determine a plurality of fourth-layer doped structure crystals based on the plurality of third-layer doped structure crystals, and each fourth-layer doped structure crystal is used as a target doped structure crystal. The fourth-layer screening criterion includes that the effective electron mass and the effective hole mass are less than a fifth threshold.

3. The method according to claim 2, characterized in that, The formula for calculating the formation energy is: AND form =And droped -AND pristine +E M -AND x Among them, E droped E represents the total energy of a doped crystal structure. pristine E represents the total energy of a LiInSe2 crystal. M E represents the total energy of the doped metal atoms in the reference state. x This represents the total energy of the replaced In atom in the reference state.

4. The method according to claim 2, characterized in that, The first threshold is 0.7 eV, the second threshold is 0.25 eV, the third threshold is 1.05 eV, and the fourth threshold is 10 eV. 4 cm -1 The fifth threshold is 1; The spatial position information of the doped crystal includes the length, width, and height of the doped crystal, as well as the angles of the horizontal, vertical, and axial axes in a Cartesian coordinate system; the spatial position information of the atoms includes the horizontal, vertical, and axial coordinates of the atoms in a Cartesian coordinate system.

5. The method according to claim 1, characterized in that, The doping concentration of metal atoms varies depending on the spatial structure of the LiInSe2 crystal.

6. The method according to claim 5, characterized in that, The spatial structure of the LiInSe2 crystal includes the I41 / amd space group and the R3m space group. When the spatial structure of the LiInSe2 crystal is the I41 / amd space group, the doping concentration of metal atoms is 50%. When the spatial structure of the LiInSe2 crystal is the R3m space group, the doping concentration of metal atoms is 1 / 3 or 2 / 3.

7. The method according to any one of claims 1 to 6, characterized in that, The metal atoms include Ga atoms, Al atoms, Sn atoms, and Sb atoms.

8. The method according to claim 7, characterized in that, The plurality of target doped crystal structures include LiIn with an I41 / amd space group structure formed by Al atom doping. 1 / 2 Al 1 / 2 Se2 crystals and LiIn with R3m space group structure formed by Sb atom doping. 2 / 3 Sb 1 / 3 Se2 crystals and LiIn 1 / 3 Sb 2 / 3 Se2 crystal.

9. A target-doped structure crystal, characterized in that, The target doped crystal structure is obtained by the LiInSe2 mid-wave infrared optoelectronic material optimization method as described in any one of claims 1 to 8, and the target doped crystal structure is LiIn. 1- x M x Se2 crystal, where M represents the doped metal atoms and x represents the doping concentration of the metal atoms.

10. A LiInSe2 mid-wave infrared optoelectronic material optimization device, comprising a processor, a memory, and computer instructions stored in the memory, characterized in that, The processor is configured to execute the computer instructions, and when the computer instructions are executed, the device implements the steps of the method as described in any one of claims 1 to 8.

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