不同缺陷对二维MoSi_(2)N_(4)的电子结构及光学性质影响

Effects of different defects on the electronic structure andoptical properties of two-dimensional MoSi_(2)N_(4)

二维材料以优良性能在各领域表现出巨大潜力,单层MoSi_(2)N_(4)材料具有非磁性半导体和良好的稳定性。采用基于密度泛函理论的第一性原理计算研究在氮、硅、钼空位下二维MoSi_(2)N_(4)的光电性质。研究结果显示:和本征二维MoSi_(2)N_(4)相比,外层氮和钼原子缺陷结构的禁带宽度缩减极大,而内层氮和硅原子缺陷结构的禁带宽度分别为0.781和0.736 eV,均有所减小。在导电类型方面,二维MoSi_(2)N_(4)因为内层氮缺陷由p型半导体转变为n型半导体。同时,各个缺陷结构均使二维MoSi_(2)N_(4)发生了不同程度的红移。二维MoSi_(2)N_(4)以材料性能优异,研究光电性能对新一代光电器件具有重要意义。

Two-dimensional materials exhibit immense latent capacity in many domain with excellent performance,and monolayer MoSi_(2)N_(4) materials have non-magnetic semiconductors and good stability.In this paper,first principles calculations based on density functional theory are used to study the photoelectric properties of intrinsic two-dimensional MoSi_(2)N_(4) in nitrogen,silicon and molybdenum vacancies.The results show that compared with the intrinsic two-dimensional MoSi_(2)N_(4),the band gap of the defective structure of the outer nitrogen and molybdenum atoms is greatly reduced,while the band gap of the inner nitrogen and silicon atomic defect structures is 0.781 eV and 0.736 eV,respectively.Moreover,the inner nitrogen defect changes the conduction type of two-dimensional MoSi_(2)N_(4) from the original P-type to N-type semiconductor.Optical properties:Each defect structure causes different degrees of redshift in 2D MoSi_(2)N_(4).Two-dimensional MoSi_(2)N_(4) has excellent material properties,and the study of optoelectronic properties is of great significance for the new generation of optoelectronic devices.