Volume 106, Number 4, May 2014
|Number of page(s)||5|
|Section||Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties|
|Published online||12 May 2014|
Is silicene stable in O2? —First-principles study of O2 dissociation and O2-dissociation–induced oxygen atoms adsorption on free-standing silicene
1 College of Physics and Communication Electronics, Jiangxi Normal University - Nanchang, Jiangxi, 330022, PRC
2 Department of Physics, University of Science and Technology of China - Hefei, Anhui, 230026, PRC
3 Key Laboratory of Photoelectronic and Telecommunication of Jiangxi Province - Nanchang, Jiangxi, 330022, PRC
Received: 10 December 2013
Accepted: 24 April 2014
The stability of free-standing silicene in O2 is an open question. In this letter, the O2 dissociation and O2-dissociation–induced O atoms adsorption on free-standing silicene are studied by using first-principles calculations. Our results show that the O2 molecule dissociates on the free-standing silicene surface easily from both the thermodynamic and kinetic points of view, which is different from the case of graphene. The dissociation reaction is an exothermic process, and the dissociated O atoms form strong bonds with Si atoms, which lowers the energy of the system substantially. On the other hand, the dissociation reaction occurs spontaneously on the free-standing silicene without overcoming any energy barrier. Furthermore, the migration and desorption of O atoms are relatively difficult under room temperature due to the strong Si-O bonds in the O-adsorbed silicene, which is in favor of forming silicon oxides. Our results provide convictive evidence to show that free-standing silicene is unstable in O2.
PACS: 73.22.-f – Electronic structure of nanoscale materials and related systems / 71.15.Mb – Density functional theory, local density approximation, gradient and other corrections
© EPLA, 2014
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.