基于graphene条带的硅纳米结构

Novel silicon nanostructures based on graphene ribbons

采用分子动力学模拟方法研究了graphene条带上生长硅纳米结构的过程,分析了不同温度下硅原子在graphene条带边沿生成的新型纳米结构.研究表明,随机分布的硅原子吸附到锯齿型graphene条带边沿在不同的温度T下可生成不同类型的硅纳米结构:300K≤T<2000K时形成无规则的团簇,2000K≤T≤2800K时形成单原子链结构,2800K<T<3900K时形成含缺陷的硅链结构,T≥3900K时硅原子逐渐替代条带边沿的碳原子直至graphene条带破坏.而硅原子吸附到扶手椅型graphene条带边沿在300K≤T<3000K内仅能形成非链状的不定型的硅纳米结构.

In this paper, we have studied formation processes of silicon nanostructures on edges of graphene ribbons by molecular dynamics simulation. We found that, Si atoms in a gas state can be absorbed on the edges of zigzag graphene ribbons, forming different types of silicon nanostructures under different temperature T, namely, amorphous clusters,chain structures, and defective chain structures in the intervals 300 K ≤ T 〈 2000 K, 2000 K ≤ T ≤2800 K and 2800 K 〈 T 〈 3900 K, respectively. At T ≥ 3900 K, carbon atoms on the edges of graphene ribbons are gradually replaced by Si atoms. For the graphene ribbons with armchair edges, existence of multiple adsorption sites does not allow growth of chain-like Si nanostructures.