From Silicene to Half-Silicane by Hydrogenation

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• 作者：Jinglan Qiu ; Huixia Fu ; Yang Xu ; Qing Zhou ; Sheng Meng ; Hui Li ; Lan Chen ; Kehui Wu
• 刊名：ACS Nano
• 出版年：2015
• 出版时间：November 24, 2015
• 年：2015
• 卷：9
• 期：11
• 页码：11192-11199
• 全文大小：736K
• ISSN：1936-086X

文摘

Graphane is graphene fully hydrogenated from both sides, forming a 1脳1 structure, where all C atoms are in sp³ configuration. In silicene, the Si atoms are in a mixed sp²/sp³ configuration; it is therefore natural to imagine a silicane structure analogous to graphane. However, a monatomic silicene sheet grown on substrates generally reconstructs into different phases, and only partially hydrogenated silicene with reconstructions had been reported before. In this work, we produce half-silicane, where one Si sublattice is fully H-saturated and the other sublattice is intact, forming a perfect 1脳1 structure. By hydrogenating various silicene phases on a Ag(111) substrate, we found that only the (2鈭?脳2鈭?)R30掳 phase can produce half-silicane. Interestingly, this phase was previously considered to be a highly defective or incomplete silicene structure. Our results indicate that the structure of the (2鈭?脳2鈭?)R30掳 phase involves a complete silicene-1脳1 lattice instead of defective fragments, and the formation mechanism of half-silicane was discussed with the help of first-principles calculations.