Stability of Hydrogen-Terminated Surfaces of Silicon Nanowires in Aqueous Solutions

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• 作者：Chunzeng Peng ; Jing Gao ; Suidong Wang ; Xiaohong Zhang ; Xinping Zhang ; Xuhui Sun
• 刊名：Journal of Physical Chemistry C
• 出版年：2011
• 出版时间：March 17, 2011
• 年：2011
• 卷：115
• 期：10
• 页码：3866-3871
• 全文大小：880K
• 年卷期：v.115,no.10(March 17, 2011)
• ISSN：1932-7455

文摘

The surface stability of silicon nanowires (SiNWs) is crucial to their applications in nanodevices, such as transistors, sensors, photovoltaic cells, Li-ion batteries, etc. In this study, X-ray photoelectron spectroscopy (XPS) has been used to systematically investigate the stability of H-terminated surfaces of SiNWs at room temperature in aqueous solutions of different pH values. The hydrogen-terminated surfaces of SiNWs show relatively poor stability in aqueous solution, which depends on the solution pH. The oxygen in the solution had little effect on the oxidation of SiNW surfaces. With pH value increases in the solution, H-terminated SiNWs exhibit a greater extent of oxidation with higher oxidation rate. In low pH solution (<7), the surface species Si鈭扥H can abundantly and stably exist and the oxidation process follows a multistep process, while, in high pH solution, the oxidation immediately happens by the assist of high concentration OH^{鈭?/sup> to form SiO₂ rapidly. The comparison of the stability of the SiNWs to that of silicon wafers is also discussed.}