A DFT study on the structures and stabilities of As-doped Sin-1 (n=2-15) clusters

作者：Kodlaa Adnan; El Taher Sabry^*

来源：Computational and Theoretical Chemistry, 2012, 992: 134-141.

DOI：10.1016/j.comptc.2012.05.022

• As-doped silicon clusters
• Structure
• Stability
• Density functional method
• HOMO-LUMO gap

The structures and relative stability of pure Si-n and AsSin-1 (n = 2-15) clusters have been investigated at the B3LYP/6-31++G(3d) level of density functional theory. In general, the As doping does not lead to fundamental changes in the geometry of the studied clusters; the effects are localized. Relative stabilities of these clusters have been analyzed based on the variation of their averaged binding energies (E-b), fragmentation energies (E-f), second differences in energy (Delta E-2), and the highest occupied and the lowest unoccupied molecular orbital (HOMO-LUMO) gaps (Delta E) with cluster size (n). The calculated values of E-f, Delta E-2, and Delta E shed light on the relatively high stability of clusters Si-12 and Si-14 in addition to the well-known magic numbers Si-6 and Si-10. According to E-b. Delta E-2, and E-f results both Si-n and AsSin-1, clusters with n = 6, 10, 12, and 14 exhibit high stability when compared to their neighbors. This has been discussed in terms of their close-packed structures rather than electronic pairing effect. The analysis indicates that Delta E of AsSin-1 clusters are significantly smaller than those of the corresponding Si-n clusters, especially for n %26gt; 4, which means that the metallic characters of AsSin-1 clusters are enhanced by As doping.

• 出版日期2012-7-15