自石墨烯问世以来，因其具有单原子层厚度、高载流子迁移率、高强度等诸多优异性能，受到了人们的广泛关注。但是由于石墨烯是零带隙材料，因此也限制了它在光电子学等一些领域的应用。类石墨烯二维材料，如单层氧化锌(ZnO)、单层六方氮化硼(h-BN)、单层二硫化钼(MoS₂)等，与石墨烯拥有类似的晶格结构，并且拥有带隙，具备良好的拓扑绝缘体效应、超导电性和光学等性质，为类石墨烯二维材料的应用提供了更多的可能。空位缺陷的产生和应变都会对材料的物理性质产生一定的影响，这在理论和实验中均已被证实。然而，空位缺陷协同应变对类石墨烯二维材料光电性质的影响研究鲜有报道。因此，本文使用基于密度泛函理论的第一性原理方法研究了单层ZnO、单层h-BN和单层MoS₂三种类石墨烯材料存在不同空位缺陷体系的电子结构以及空位缺陷协同等双轴应变对单层ZnO、单层h-BN和单层MoS₂的稳定性和光学性质的影响，并对光学性质的影响进行了比较。

(1) 研究了单层ZnO及其不同空位缺陷体系的电子结构以及空位缺陷协同等双轴应变对单层ZnO的稳定性和光学性质的影响。结果表明，单层ZnO是带隙为1.66 eV的直接带隙半导体。当单层ZnO存在O空位缺陷时，带隙为2.22 eV，电导率降低。当单层ZnO存在Zn空位缺陷时，带隙为1.85 eV，导电性增强。单层ZnO及其不同空位缺陷体系的应变能随着应变的增加而增加。光学参数会随应变的增加向着能量较低的区域移动，空位缺陷协同应变对单层ZnO光学性质的影响主要集中在能量较低的区域。此外，O空位缺陷协同应变对光学性质的影响更加显著。

(2) 研究了单层h-BN及其不同空位缺陷体系的电子结构，并探究了空位缺陷协同等双轴应变对单层h-BN的稳定性和光学性质的影响。结果表明，单层h-BN是带隙为4.67 eV的宽带隙半导体。在单层h-BN出现B空位缺陷后，系统表现出金属性与磁性。在单层h-BN出现N空位缺陷后，系统表现出半金属性与磁性。单层h-BN具有最佳的稳定性，出现空位缺陷后单层h-BN的稳定性有所下降。单层h-BN的光学参数随着拉伸应变的增加发生红移，随着压缩应变的增加发生蓝移。空位缺陷协同应变可以丰富单层h-BN的光学应用，并且B空位缺陷协同应变对光学性质的影响更加显著。

(3) 对单层MoS₂及其不同空位缺陷体系的电子结构的异同进行了比较，并研究了空位缺陷协同等双轴应变对单层MoS₂的稳定性和光学性质的影响。结果表明，单层MoS₂是直接带隙为1.73 eV的半导体。当单层MoS₂存在Mo空位缺陷时，带隙显著减小，金属性增强。当单层MoS₂存在S空位缺陷时，带隙类型由直接带隙转变为间接带隙，禁带宽度减小。单层MoS₂的结构最为稳定，出现空位缺陷后稳定性有所降低。单层MoS₂的光学常数在拉伸应变和压缩应变下具有相对的变化趋势。空位缺陷协同应变对单层MoS₂的光学性质影响在能量较低的区域更加明显，且Mo空位缺陷协同应变对光学性质的影响更大。

Since the advent of graphene, it has been widely concerned because of its excellent properties such as monoatomic layer thickness, high carrier mobility and high strength. However, graphene is a zero-band gap material, which also limits its application in some fileds such as optoelectronics. Graphene-like two-dimensional materials, such as monolayer zinc oxide (ZnO), monolayer hexagonal boron nitride (h-BN), monolayer molybdenum disulfide (MoS₂), etc., have similar lattice structure with graphene, and have band gap, good topological insulator effect, superconductivity and optical properties, providing more possibilities for the application of graphene like two-dimensional materials. The generation and strain of vacancy defects will have a certain impact on the physical properties of materials, which has been confirmed in theory and experiment. However, there are few reports about the effect of vacancy defect synergetic strain on the optoelectronic properties of graphene-like two-dimensional materials. Therefore, the first principle method based on density functional theory is used to study the electronic structures of three kinds of graphene materials, namely, monolayer ZnO, monolayer h-BN and monolayer MoS₂, with different vacancy defect systems, as well as the vacancy defect synergetic equibiaxial strain on the stability and optical properties of monolayer ZnO, monolayer h-BN, and monolayer MoS₂. And the effects of vacancy defect synergetic strain on their optical properties are compared.

(1) The electronic structures of monolayer ZnO and its different vacancy defect systems and the effect of vacany defect synergetic equibiaxial strain on the stability and optical properties of monolayer ZnO were studied. The results indicate that monolayer ZnO is a direct bandgap semiconductor with a bandgap of 1.66 eV. When monolayer ZnO has O vacancy defect, the band gap is 2.22 eV, and the conductivity decreases. When monolayer ZnO has Zn vacancy defect, the band gap is 1.85 eV, and the conductivity is enhanced. The strain energy of monolayer ZnO and its different vacancy defect systems increases with the increase of strain. The optical parameters will move towards the lower energy region as strain increase, and the effect of vacancy defect synergetic strain on the optical properties of monolayer ZnO is mainly concentrated in the lower energy region. In addition, the effect of O vacancy defect synergetic strain on optical properties is more significant.

(2) The electronic structure of monolayer h-BN and its different vacancy defect systems were studied, and the effect of vacancy defect synergetic equibiaxial strain on the stability and optical properties of monolayer h-BN were explored. The results show that the monolayer h-BN is a broadband gap semiconductor with a band gap of 4.67 eV. After the monolayer h-BN has B vacancy defect, the system shows metallicity and magnetism. After the monolayer h-BN has N vacancy defect, the system shows semi-metallic property and magnetism. Monolayer h-BN has the best stability and the stability of monolayer h-BN decreases when vacancy defect appears. The optical parameters of the monolayer h-BN will redshift with the increase of tensile strain, and will blueshift with the increase of compression strain. The vacancy defect synergetic strain can enrich the optical applications of monolayer h-BN, and the effect of B vacancy defect synergetic strain on optical properties is more significant.

(3) The similarities and differences of the electronic structures of the monolayer MoS₂ and its different vacancy defect systems were compared, and the effect of vacancy defect synergetic equibiaxial strain on the stability and optical properties of monolayer MoS₂ were studied. The results show that monolayer MoS₂ is a semiconductor with a direct band gap of 1.73 eV. When monolayer MoS₂ has Mo vacancy defect, the band gap decreases significantly and the metallicity increases. When S vacancy defect appears in monolayer MoS₂, the type of band gap changes from direct band gap to indirect band gap, and the band gap decreases. The structure of monolayer MoS₂ is the most stable, and the stability decreases after vacancy defects appear. The optical constants of the monolayer MoS₂ exhibit a relative trend of change under tensile and compressive strains. The effect of vacancy defect synergetic strain on the optical properties of monolayer MoS₂ is more obvious in the lower energy region, and the effect of Mo vacancy defect synergetic strain on the optical properties is greater.