桥位吸附硼原子硅烯的结构与电子性质

Structure and Electronic Properties of Silicene with Boron Atoms Adsorbed at Bridge Site

基于密度泛函理论的第一性原理,研究了新型类石墨烯材料硅烯进行桥位吸附硼原子之后的微观结构和电子性质,并与原始硅烯结构进行对比分析。研究发现3种覆盖度下,4×4桥位吸附硼原子硅烯超晶胞均为放热反应,吸附能最大为-2.56 eV。吸附过程中从硅原子到硼原子产生1.14个电子转移并形成稳定共价键。相比于直接带隙半金属结构的原始硅烯,桥位吸附硼原子硅烯在K点处打开0.15 eV直接带隙,同时引入0.67μB磁矩。

Based on the first principles of density functional theory(DFT),the microstructure and electronic properties of a kind of new graphene⁃like material,the silicene with boron atoms adsorbed at bridge site,were studied and also compared with the original silicene structure.It is found that under 3 coverage conditions,the silicene supercells with boron atoms adsorbed at 4×4 bridge sites all experience exothermic reactions with the maximum adsorption energy of-2.56 eV.During the adsorption process,1.14 electrons are transferred from silicon atom to boron atom and a stable covalent bond is formed.Compared with the original silicene that is the semi⁃metal structure with a direct band gap,the new silicene with boron atoms adsorbed at bridge site has opened a 0.15 eV direct band gap at K point and introduces a 0.67μB magnetic moment.