Method for calculating and regulating boron arsenide band gap based on first principle
By using density functional theory based on first principles and software calculations, the bandgap of boron arsenide was tuned, solving the problem of limited tuning range in traditional methods. This achieved efficient bandgap tuning and reduced experimental costs, providing theoretical support for semiconductor device design.
Patent Information
- Application Number
- CN202511102420.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-07
- Publication Date
- 2025-11-21
AI Technical Summary
Existing technologies are difficult to effectively control the band gap of boron arsenide. Traditional methods have limited control range, are prone to introducing impurities and defects, and cannot meet the diverse needs of different scenarios.
By employing density functional theory based on first principles, and by uniaxially stretching or compressing boron arsenide unit cells along a high-symmetry direction, combined with VASP and VASPkit software for static calculations and band structure analysis, band gap data is extracted to achieve deep strain control.
This study achieved continuous control of the boron arsenide bandgap, significantly reduced R&D costs, improved experimental efficiency, provided reliable theoretical basis, and offered a theoretical framework for the design of novel semiconductor devices.
Smart Images
Figure CN120998370A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductor technology, specifically to a method for calculating and controlling the bandgap of boron arsenide based on first-principles calculations. Background Technology
[0002] With the rapid development of the semiconductor industry, the demand for performance control of semiconductor materials is becoming increasingly urgent. Bandgap, as a core characteristic parameter of semiconductor materials, directly determines their electrical, optical, and other physical properties, and is a key factor affecting device functionality and application scenarios. For example, wide-bandgap semiconductors are suitable for high-temperature, high-frequency devices, while narrow-bandgap semiconductors have important applications in infrared detection, optoelectronic devices, and other fields. Therefore, achieving precise control of the bandgap of semiconductor materials is of great significance for expanding their application range and optimizing device performance.
[0003] Boron arsenide (BAs), as an emerging third-generation semiconductor material, has shown great application potential in high-temperature electronic devices and power devices due to its excellent thermal conductivity, high carrier mobility, and good chemical stability. However, the fixed bandgap of natural boron arsenide makes it difficult to meet the diverse needs of different scenarios, limiting its flexible application in multiple fields. Traditional bandgap tuning methods mainly include doping and alloying, but these methods have problems such as limited tuning range, easy introduction of impurities and defects, and damage to the intrinsic properties of the material. For example, doping may lead to enhanced carrier scattering, reducing the conductivity of the material; alloying may affect the stability of the material due to compositional inhomogeneity.
[0004] First-principles calculation methods provide efficient theoretical guidance for the control of material properties. Density functional theory (DFT), as an important branch of quantum mechanics, can accurately describe the electronic structure of materials at the atomic scale and predict their physicochemical properties without relying on experimental parameters. It has been widely applied in the study of semiconductor material performance control. Predicting the effect of strain on the band gap of materials through theoretical calculations can significantly reduce experimental trial-and-error costs and shorten the research and development cycle. However, research on deep strain band gap control of boron arsenide is still in its early stages, lacking systematic theoretical methods and a summary of rules, making it difficult to effectively guide experimental design. Therefore, developing a first-principles-based method for deep strain control of the boron arsenide band gap has significant theoretical and applied value. Summary of the Invention
[0005] The purpose of this section is to outline some aspects of the embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.
[0006] Therefore, the object of the present invention is to provide a method for calculating and controlling the band gap of boron arsenide based on first-principles calculations, so as to solve the problems mentioned in the background art.
[0007] To address the aforementioned technical problems, according to one aspect of the present invention, the present invention provides the following technical solution:
[0008] A method for controlling the bandgap of boron arsenide based on first-principles calculations, comprising the following steps:
[0009] S1. Modeling: Constructing the primitive cell of boron arsenide unit cell;
[0010] S2. Strain calculation: Boron arsenide is subjected to uniaxial stretching or compression along the high symmetry direction of its lattice, and other lattice parameters outside the high symmetry direction are allowed to relax freely during the stretching or compression process.
[0011] S3. Static Calculation: Based on the lattice state obtained in step S2, perform static calculations to obtain electronic structure-related files;
[0012] S4. Band structure calculation: Based on the electronic structure related files in step S3, select the K-point path that contains all inequivalent high symmetry points and perform band structure calculation.
[0013] S5. Bandgap extraction: Extract bandgap data from the band structure calculation results in step S4 to obtain the regulation law of the boron arsenide bandgap by depth strain.
[0014] As a preferred embodiment of the method for calculating and controlling the band gap of boron arsenide based on first principles as described in this invention, in step S2, the high symmetry direction includes the Z-axis direction of the cubic unit cell, the face diagonal direction of the cubic unit cell (i.e., the direction where the X and Y axis components are equal and the Z axis component is 0), and the body diagonal direction of the cubic unit cell (i.e., the direction where the X, Y, and Z axis components are equal).
[0015] As a preferred embodiment of the method for calculating and controlling the boron arsenide bandgap based on first principles according to the present invention, in step S2, during uniaxial tension or compression, the stress matrix [σ] in the rectangular coordinate system is used as the control reference.
[0016]
[0017] Where, τ xy =τ yx , τ xz =τ zx , τ yz =τ zy When stretched or compressed in a certain direction, only the stress component corresponding to that direction is controlled, while the other 5 stress components relax freely.
[0018] As a preferred embodiment of the method for calculating and controlling the bandgap of boron arsenide based on first-principles calculations according to the present invention, in step S3, the electronic structure-related files include CHG files, CHGCAR files, and WAVECAR files.
[0019] As a preferred embodiment of the method for calculating and controlling the bandgap of boron arsenide based on first-principles calculations described in this invention, the band structure calculation employs the hybrid functional HSE06 method.
[0020] As a preferred embodiment of the method for calculating and controlling the bandgap of boron arsenide based on first-principles calculations described in this invention, the bandgap extraction is achieved using the VASPKT software. Specifically, after entering the "VASPKT" command in the bandgap calculation directory, the "252" command is further entered to generate a BAND_GAP file to obtain bandgap data.
[0021] As a preferred embodiment of the method for controlling the boron arsenide bandgap based on first-principles calculations according to the present invention, the bandgap control law of the depth strain includes:
[0022] When compressed along the Z-axis of the cubic unit cell, the band gap decreases slowly when the strain is ≤0.13, decreases rapidly when the strain is >0.13, and drops to 0.5 eV when the strain reaches 0.18.
[0023] When compressed along the diagonal direction of the cubic unit cell face, the band gap decreases linearly with increasing strain until it disappears when the strain reaches 0.11.
[0024] When compressed along the diagonal of the cubic unit cell, the band gap decreases linearly with increasing strain until it disappears when the strain reaches 0.13.
[0025] When stretched along the Z-axis of the cubic unit cell, the band gap decreases linearly with increasing strain.
[0026] When stretched along the diagonal of a cubic unit cell, the band gap decreases slowly when the strain is ≤0.105, and decreases rapidly when the strain is >0.105.
[0027] When stretched along the diagonal of a cubic unit cell face, the band gap increases with increasing strain when the strain is ≤0.127, and decreases with increasing strain when the strain is >0.127.
[0028] Compared with the prior art, the beneficial effects of the present invention are:
[0029] 1. This invention achieves continuous bandgap control by applying uniaxial tensile or compressive strain to boron arsenide along the Z-axis, diagonal, and bulk diagonal directions of the cubic unit cell, covering a wide range of variations from bandgap disappearance (metallization) to bandgap increase. For example, when stretched along the diagonal direction of the cubic unit cell face, the bandgap can first increase and then decrease, with the maximum control amplitude significantly better than traditional doping methods, meeting the diverse bandgap requirements of different scenarios.
[0030] 2. This invention is based on density functional theory and uses VASP and VASPkit software to achieve full-process quantitative calculations, enabling accurate prediction of bandgap variation patterns (such as critical strain values and bandgap variation rates) under different strain conditions before experiments. This process does not require the consumption of actual materials or the construction of complex experimental setups, effectively reducing the time wastage and material consumption caused by blind experiments, and significantly reducing R&D costs (estimated to reduce the number of experimental trials by more than 50%).
[0031] 3. This invention clarifies the quantitative relationship between depth strain and bandgap variation through strict lattice strain control (e.g., fixed strain in a single direction, free relaxation of other parameters), avoiding performance fluctuations caused by impurity introduction in traditional methods. The calculation process is based on standardized first-principles procedures (e.g., hybrid functional HSE06 method, high-symmetry K-point path selection), and the results are highly reproducible, providing a reliable theoretical basis for experimental preparation.
[0032] 4. The computational steps of this invention are clear and controllable. From cell modeling to bandgap extraction, all are implemented using mature software, requiring no complex experimental skills. Furthermore, this method can be extended to strain control research on other semiconductor materials, providing a general theoretical framework for the design and development of novel semiconductor devices. Attached Figure Description
[0033] To more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and detailed embodiments. 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. Wherein:
[0034] Figure 1 A schematic diagram of boron arsenide unit cells provided by the present invention;
[0035] Figure 2 The present invention provides an interactive interface for entering the vaspkit command in the terminal interface of a Linux system.
[0036] Figure 3 This invention provides the output interface after inputting 252 in the VASPKit software;
[0037] Figure 4 The band gap obtained after stretching and compression according to the present invention is shown in the figure, where T represents stretching and C represents compression. Detailed Implementation
[0038] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
[0039] This invention provides a method for controlling the band gap of boron arsenide based on first-principles calculations. Utilizing density functional theory developed from quantum theory, the electronic structure of boron arsenide can be controlled through deep strain. The theoretical calculation process of this invention is simple and efficient, effectively guiding sample preparation and experimental design, significantly improving experimental efficiency, and reducing time and material costs.
[0040] The method for controlling the boron arsenide bandgap based on first-principles calculations involves the following steps:
[0041] S1. Modeling: Based on the atomic structure of the crystal lattice, construct as follows: Figure 1 The primitive cell of the boron arsenide unit cell is shown;
[0042] S2. Strain calculation: Boron arsenide is subjected to uniaxial stretching or compression along its high symmetry direction, and other lattice parameters outside the high symmetry direction are allowed to relax freely during the stretching or compression process. Specifically, the high symmetry direction includes the Z-axis direction along the cubic unit cell, the face diagonal direction of the cubic unit cell (i.e., the direction where the X and Y axis components are equal and the Z axis component is 0), and the body diagonal direction of the cubic unit cell (i.e., the direction where the X, Y, and Z axis components are equal). During uniaxial stretching or compression, the stress matrix [σ] in the rectangular coordinate system is used as the control reference.
[0043]
[0044] Where, τ xy =τ yx , τ xz =τ zx , τ yz =τ zy When stretched or compressed in a certain direction, only the stress component corresponding to that direction is controlled, while the other 5 stress components relax freely.
[0045] S3. Static Calculation: Based on the lattice state obtained in step S2, perform static calculations to obtain electronic structure-related files, including CHG files, CHGCAR files, and WAVECAR files.
[0046] S4. Band structure calculation: Based on the electronic structure related files in step S3, select the K-point path that contains all inequivalent high symmetry points and perform band structure calculation.
[0047] When balancing the structure, the selected point K is:
[0048] 0.00000000000.00000000000.0000000000Γ
[0049] 0.00000000000.50000000000.5000000000X
[0050] 0.25000000000.50000000000.7500000000W
[0051] 0.37500000000.37500000000.7500000000K
[0052] 0.00000000000.00000000000.0000000000Γ
[0053] 0.50000000000.50000000000.5000000000L
[0054] It is important to note that as tensile or compressive strain is applied, the crystal structure changes. The high-symmetry K-points in the equilibrium structure become no longer completely equivalent after lattice deformation. The K-point path for band structure calculations must include all inequivalent high-symmetry points. After selecting the K-points, a pseudopotential is chosen for band structure calculations. In this embodiment, the hybrid functional HSE06 (Heyd-Scuseria-Ernzerhof 2006, HSE06) method, which has relatively high accuracy in semiconductor bandgap calculations, is used. Because the hybrid functional HSE06 method requires the calculation of the Hartree-Fock exchange energy, its computational load is much larger than that of the traditional GGA functional method, requiring sufficient computational resources and time.
[0055] S5. Bandgap Extraction: After calculating the band structure, the bandgap data needs to be extracted from the results. Here, the VASPKT software is used. In the band structure calculation directory, enter the VASPKT command, and then, following the prompts on the interactive interface, enter the command 252 to generate a BAND_GAP file to obtain the bandgap data. Figure 2 and Figure 3 As shown.
[0056] Figure 4 The band gap is obtained by stretching and compressing boron arsenide unit cells, such as Figure 4 As shown, the specific law governing the control of bandgap by depth strain is as follows:
[0057] When compressed along the Z-axis of the cubic unit cell, the band gap decreases slowly when the strain is ≤0.13, decreases rapidly when the strain is >0.13, and drops to 0.5 eV when the strain reaches 0.18.
[0058] When compressed along the diagonal direction of the cubic unit cell face, the band gap decreases linearly with increasing strain until it disappears when the strain reaches 0.11.
[0059] When compressed along the diagonal of the cubic unit cell, the band gap decreases linearly with increasing strain until it disappears when the strain reaches 0.13.
[0060] When stretched along the Z-axis of the cubic unit cell, the band gap decreases linearly with increasing strain.
[0061] When stretched along the diagonal of a cubic unit cell, the band gap decreases slowly when the strain is ≤0.105, and decreases rapidly when the strain is >0.105.
[0062] When stretched along the diagonal of a cubic unit cell face, the band gap increases with increasing strain when the strain is ≤0.127, and decreases with increasing strain when the strain is >0.127.
[0063] Although the present invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, as long as there is no structural conflict, the features in the disclosed embodiments can be combined with each other in any manner. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.
Claims
1. A method for controlling the bandgap of boron arsenide based on first-principles calculations, characterized in that, The steps are as follows: S1. Modeling: Constructing the primitive cell of boron arsenide unit cell; S2. Strain calculation: Boron arsenide is subjected to uniaxial stretching or compression along the high symmetry direction of its lattice, and other lattice parameters outside the high symmetry direction are allowed to relax freely during the stretching or compression process. S3. Static Calculation: Based on the lattice state obtained in step S2, perform static calculations to obtain electronic structure-related files; S4. Band structure calculation: Based on the electronic structure related files in step S3, select the K-point path that contains all inequivalent high symmetry points and perform band structure calculation. S5. Bandgap extraction: Extract bandgap data from the band structure calculation results in step S4 to obtain the regulation law of the boron arsenide bandgap by depth strain.
2. The method for controlling the boron arsenide bandgap based on first-principles calculations according to claim 1, characterized in that, In step S2, the high symmetry direction includes the direction along the Z-axis of the cubic unit cell, the direction along the face diagonal of the cubic unit cell (i.e., the direction where the X and Y axis components are equal and the Z axis component is 0), and the direction along the body diagonal of the cubic unit cell (i.e., the direction where the X, Y, and Z axis components are equal).
3. The method for controlling the boron arsenide bandgap based on first-principles calculations according to claim 1, characterized in that, In step S2, during uniaxial tension or compression, the stress matrix [σ] in the Cartesian coordinate system is used as the control reference. Where, τ xy =τ yx , τ xz =τ zx , τ yz =τ zy When stretched or compressed in a certain direction, only the stress component corresponding to that direction is controlled, while the other 5 stress components relax freely.
4. The method for controlling the boron arsenide bandgap based on first-principles calculations according to claim 1, characterized in that, In step S3, the electronic structure-related files include CHG files, CHGCAR files, and WAVECAR files.
5. The method for controlling the boron arsenide bandgap based on first-principles calculations according to claim 1, characterized in that, The band structure calculation employs the hybrid functional HSE06 method.
6. The method for controlling the boron arsenide bandgap based on first-principles calculations according to claim 1, characterized in that, The bandgap extraction is achieved using the VASPKIT software. Specifically, after entering the "vaspkit" command in the bandgap calculation directory, the "252" command is then entered to generate a BAND_GAP file to obtain bandgap data.
7. The method for controlling the boron arsenide bandgap based on first-principles calculations according to claim 1, characterized in that, The modulation law of bandgap by the depth strain includes: When compressed along the Z-axis of the cubic unit cell, the band gap decreases slowly when the strain is ≤0.13, decreases rapidly when the strain is >0.13, and drops to 0.5 eV when the strain reaches 0.
18. When compressed along the diagonal direction of the cubic unit cell face, the band gap decreases linearly with increasing strain until it disappears when the strain reaches 0.
11. When compressed along the diagonal of the cubic unit cell, the band gap decreases linearly with increasing strain until it disappears when the strain reaches 0.
13. When stretched along the Z-axis of the cubic unit cell, the band gap decreases linearly with increasing strain. When stretched along the diagonal of a cubic unit cell, the band gap decreases slowly when the strain is ≤0.105, and decreases rapidly when the strain is >0.
105. When stretched along the diagonal of a cubic unit cell face, the band gap increases with increasing strain when the strain is ≤0.127, and decreases with increasing strain when the strain is >0.127.