二维缺陷GaAs电子结构和光学性质 第一性原理研究
First-principles study on electronic structure and optical properties of Two-dimensional defect GaAs

采用基于密度泛函理论的第一性原理方法计算了存在Ga空位缺陷和掺杂B原子的二维GaAs的能带结构、态密度和光学性质。计算结果表明空位缺陷二维GaAs显示出金属特性，B原子的引入使体系变为间接带隙半导体，禁带宽度为0.35 eV。态密度计算发现体系低能带主要由Ga的s态、p态、d态和As 的s态、p态构成；高能带主要由Ga和As的s态、p态构成。掺杂B原子与存在空位缺陷的二维GaAs相比，静态介电常数相对较低，变为8.42，且易于吸收紫外光，在3.90 - 8.63 eV能量范围具有金属反射特性，反射率达到52%。
The band structure, density of states and optical properties of two-dimensional GaAs with Ga vacancy defects and doped B atoms are calculated by the first-principles method based on density functional theory. The results show that two-dimensional GaAs with vacancy defects exhibits metallic properties. The introduction of B atoms makes the system into an indirect band gap semiconductor with a band gap of 0.35 eV. The calculation of the density of states shows that the low-energy band of the system is mainly composed of s states, p states, d states of Ga and s states and p states of As. The energy bands are mainly composed of s and p states of Ga and As. Compared with the two-dimensional GaAs of vacancy defects, the static dielectric constant of doped B atoms is relatively low. It is easy to absorb ultraviolet light and exhibits metal reflection characteristics in 3.90 - 8.63 eV energy range, with reflectivity of 52%.