论文标题
揭示σ3{112} si晶粒边界本地结构在杂质隔离中的作用
Revealing the role of Σ3{112} Si grain boundary local structures in impurity segregation
论文作者
论文摘要
硅晶界（SI-GB）的界面结构在化学功能化中起决定性的作用，并且对材料的各种物理化学特性具有影响。因此，当材料用于高性能技术应用中时，GB界面特别重要。在这里，我们从第一原理研究了GB接口的角色，通过对两个不同的$σ$ 3 \ {112 \} Si-GB模型提供原子的理解。这些型号为（1 $ \ times $ 1）和（1 $ \ times $ 2）$σ$ 3 \ {112 \} Si-gb，会导致不同的结构重建。从这两个模型开始，我们已经证明几何优化在GB界面的结构重建以及其属性上具有重要作用。因此，我们讨论了定义最佳放松方案的不同方法。在（1 $ \ times $ 1）和（1 $ \ times $ 2）模型中，本地结构的影响也已在空缺的存在下进行了研究，在空缺的存在下，不同的价值杂质（C，N，H，O）可以分离。我们研究了（1 $ \ times $ 1）和（1 $ \ times $ 2）模型中的本地结构如何通过空缺和杂质的存在来修改。这些结构修饰已与GBS的能量和电子特性的变化相关。 （1 $ \ times $ 1）和（1 $ \ times $ 2）模型的行为被证明是显着不同的。根据$σ$ 3 \ {112 \} si-gb中存在的局部结构的类型，与空位的相互作用和C，N，H和O的隔离显着不同。
The interfacial structure of a silicon grain boundary (Si-GB) plays a decisive role on its chemical functionalization and has implications in diverse physical-chemical properties of the material. Therefore, GB interface is particularly relevant when the material is employed in high performance technological applications. Here, we studied from first principles the role of GB interface by providing an atomistic understanding of two different $Σ$3\{112\} Si-GB models. These models are (1$\times$1) and (1$\times$2) $Σ$3\{112\} Si-GBs which lead to different structural reconstruction. Starting from these two models, we have shown that geometry optimization has an important role on the structural reconstruction of the GB interface and therefore on its properties. For this reason, we discussed different methodologies to define an optimal relaxation protocol. The influence of the local structures in (1$\times$1) and (1$\times$2) models have also been investigated in the presence of vacancies where different light impurities of different valency (C, N, H, O) can segregate. We studied how local structures in (1$\times$1) and (1$\times$2) models are modified by the presence of vacancies and impurities. These structural modifications have been correlated with the changes of the energetics and electronic properties of the GBs. The behavior of (1$\times$1) and (1$\times$2) models demonstrated to be significantly different. The interaction with vacancies and the segregation of C, N, H and O are significantly different depending on the type of local structures present in $Σ$3\{112\} Si-GB.
