单层h-BN作为一种宽带隙材料，不仅在其晶体结构和参数上与石墨烯颇为相似， 更是在性质特性上有诸多共同点，因此，单层h-BN常被形象地称为“白石墨”。该材 料以其卓越的力学性能、出色的热导率、强大的电介质特性以及深紫外光吸收特性等 物理性质，吸引了广大学者的目光。目前已有研究证实，掺杂和应变在调控材料的电 子结构和物理特性方面均展现出显著效果。然而，关于在等双轴应变下掺杂Al原子的 单层h-BN的行为，以及单层h-BN在不同应变类型下的表现，尚未见报道。基于此， 本研究采用基于密度泛函理论的第一性原理方法，系统探讨了掺杂与应变对单层h-BN 的稳定性、电子结构以及光学特性的调控作用，主要研究内容如下： (1) 研究了Al掺杂和等双轴应变对单层h-BN的光电性质影响。研究结果显示， 等双轴拉伸应变使得材料结构更加稳定，而等双轴压缩应变则导致结构稳定性降低。 当单层h-BN掺杂Al时，其带隙显著减小，且Al的掺杂浓度越高，带隙减小的幅度越 大。此外，等双轴应变对单层h-BN的带隙调控效果尤为显著。在光学性能方面，Al 掺杂导致材料的介电函数和光学常数峰值降低，且峰值随着Al浓度的增加而进一步减 小。当对未掺杂、低浓度Al掺杂和高浓度Al掺杂三种体系施加等双轴拉伸应变时， 材料的光学性质均呈现红移趋势，而对此三种体系施加等双轴压缩应变则均导致蓝移。 特别在单层h-BN掺杂两个Al原子并施加-9%的等双轴应变时，其光学性能发生了显 著变化。这一研究为单层h-BN在自旋电子器件和光电子器件领域的应用提供了理论支 持。 (2) 进一步探讨了单轴应变和等双轴应变对单层h-BN光电性质的影响。实验数据 表明，等双轴应变相较于单轴应变对材料稳定性的影响更为显著，特别是压缩应变对 单层h-BN的稳定性产生了明显影响。单层h-BN是一种带隙为4.67eV的间接带隙材 料，而等双轴应变对其带隙宽度的影响超过了单轴应变，拉伸应变对带隙宽度变化的 影响大于压缩应变，且带隙宽度随着应变绝对值的增大而逐渐减小。在光学性能方面， 等双轴应变的影响大于单轴应变，无论是等双轴应变还是单轴应变，单层h-BN的光学 性质在拉伸应变下峰值减小并出现红移，在压缩应变下峰值增大并出现蓝移，单层h BN在拉伸和压缩应变下展现了截然相反的光学变化趋势。总体而言，等双轴应变对单 层h-BN的力学性能、电子结构和光学性能的影响均超过了单轴应变。 本研究不仅深化了我们对单层h-BN在掺杂和应变调控下性能变化的理解，更为其 未来在电子器件领域的应用提供了理论基础和实验指导。

monolayer h-BN, as a wide-band gap material, not only has its crystal structure and parameters quite similar to graphene, but also has many common characteristics in nature, so monolayer h-BN is often graphically called "white graphite". This material has attracted the attention of scholars for its excellent mechanical properties, excellent thermal conductivity, strong dielectric properties and deep ultraviolet light absorption properties. Previous studies have shown that doping and strain are both effective means to regulate the electronic structure and physical properties of materials. However, there are no relevant reports on the regulation of monolayer h-BN doped with Al atoms under equibiaxial strain and the performance of monolayer h-BN under different strain types have not been reported. In view of this, the effects of doping and strain on the stability, electronic structure and optical properties of monolayer h-BN are investigated by using the first principles method based on density functional theory, and the main studies are as follows: (1) The effects of Al doping and equibiaxial strain on the optoelectronic properties of monolayer h-BN were investigated. The results show that equibiaxial tensile strain makes the material structure more stable, while equibiaxial compressive strain leads to a decrease in structural stability. When the monolayer h-BN is doped with Al, its bandgap decreases significantly, and the higher the doping concentration of Al, the greater the bandgap decrease. In addition, the band gap modulation effect of equibiaxial strain is particularly significant for monolayer h-BN. In terms of optical properties, the peaks of dielectric function and optical constant decrease due to Al doping, and the peaks decrease further with the increase of Al concentration. When the equibiaxial tensile strain is applied to the undoped, low concentration Al doped and high concentration Al doped systems, the optical properties of the materials show a redshift trend, while the equibiaxial compressive strain is applied to the three systems, resulting in a blue shift. In particular, the optical properties of h-BN monolayers change significantly when two Al atoms are doped and an equibiaxial strain of −9% is applied. This study provides theoretical support for the application of monolayer h-BN in the field of spintronic and optoelectronic devices. (2) The effects of uniaxial strain and equibiaxial strain on the optoelectronic properties of monolayer h-BN were further investigated. The experimental data show that the effect of equibiaxial strain on the material stability is more significant compared with that of uniaxial strain, especially the compressive strain has a significant effect on the stability of monolayer h BN. The monolayer h-BN is an indirect bandgap material with a bandgap of 4.67 eV, and the effect of equibiaxial strain on its bandgap width exceeds that of uniaxial strain, and the effect of tensile strain on the change of bandgap width is greater than that of compressive strain, and the bandgap width decreases with the increase of the absolute value of strain. In terms of optical properties, the effect of equibiaxial strain is larger than that of uniaxial strain, whether equibiaxial strain or uniaxial strain, the optical properties of the monolayer h-BN decrease in peak value with red shift under tensile strain, and increase in peak value with blue shift under compressive strain, and the monolayer h-BN exhibits diametrically opposite optical trends under tensile and compressive strains. Overall, the effects of equibiaxial strain on the mechanical properties, electronic structure and optical properties of monolayer h-BN outweigh those of uniaxial strain. This study not only deepened our understanding of the properties of monolayer h-BN under doping and strain regulation, but also provided theoretical basis and experimental guidance for its future application in the field of electronic devices.