运用密度泛函理论下的广义梯度近似和交换关联函数对Cu吸附(SiO2)n(n=1—8)团簇的几何结构、电荷分布、稳定性和电子性质进行了较详细的研究,结果表明:Cu原子易于和带有悬挂键的Si原子作用并形成"铜岛膜";Cu吸附(SiO2)n团簇后Si原子失去电子能力减弱,O原子得到电子能力增强;Cu(SiO2)n(n=1—8)团簇与(SiO2)n(n=1—8)主体团簇稳定性上具有相似性,吸附Cu后团簇能隙明显降低,并接近近红外区域.
Equilibrium geometries,charge distributions,stabilities,and electronic properties of the Cu-adsorbed (SiO2) n(n = 1—8) clusters are investigated by using the density functional theory in the generalized gradient approximation for exchange-correlation functional.The results show that the Ag atom preferably binds to silicon atom with dangling bond,and the incoming Ag atoms tend to cluster on the existing Ag cluster leading to the formation of Ag islands.Therefore the ability for Si to lose electron is weaker,while the ability for Si to gain electron is stronger.In addition,the energy gaps between the highest occupied and the lowest unoccupied molecular orbitals remarkably decrease compared with the pure (SiO2)n(n = 1—8) clusters,eventually approaching the near infrared radiation region.