Oxidation Pattern of Small Silicon Oxide Clusters:  Structures and Stability of Si6O n (n = 1−12)

• Published in: The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Molecules, spectroscopy, kinetics, environment, & general theory, 2006-07, Vol.110 (26), p.8151-8157
• Main Authors: Zang, Q. J, Su, Z. M, Lu, W. C, Wang, C. Z, Ho, K. M
• Format: Article
• Language: English
• ISSN: 1089-5639; 1520-5215
• DOI: 10.1021/jp061517l

We have performed systematic ab initio calculations to study the structures and stability of Si6O n clusters (n = 1−12) in order to understand the oxidation process in silicon systems. Our calculation results show that oxidation pattern of the small silicon cluster, with continuous addition of O atoms, extends from one side to the entire Si cluster. Si atoms are found to be separated from the pure Si cluster one-by-one by insertion of oxygen into the Si−O bonds. From fragmentation energy analyses, it is found that the Si-rich clusters usually dissociate into a smaller pure Si clusters (Si5, Si4, Si3, or Si2), plus oxide fragments such as SiO, Si2O2, Si3O3, Si3O4, and Si4O5. We have also studied the structures of the ionic Si6O n ± (n = 1−12) clusters and found that most of ionic clusters have different lowest-energy structures in comparison with the neutral clusters. Our calculation results suggest that transformation Si6O n +(a) + O → Si6O n +1 +(a) should be easier.