Growth of Nanogold at Interfaces between Locally Induced Naked Silicon Surfaces and Pure HAuCl4 Solutions
Growth of Nanogold at Interfaces between Locally Induced Naked Silicon Surfaces and Pure HAuCl4 Solutions
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纳米金在局部诱导裸露硅表面和纯 HAuCl4 溶液之间界面处的生长
DOI：
10.1149/2.0261614jes
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发表时间：
2016
影响因子：
3.9
通讯作者：
Kazuyuki Hirao
中科院分区：
文献类型：
--
作者：
Hiroki Itasaka;Masayuki Nishi;Masahiro Shimizu;Kazuyuki Hirao
我们描述并通过实验验证了在局部诱导的裸硅表面和纯 HAuCl 4 溶液之间的界面处金纳米结构的区域选择性化学沉积的机制。我们之前证明，当基板暴露于纯 HAuCl 4 溶液时，金纳米结构会选择性地在硅基板的聚焦离子束 (FIB) 照射区域生长。我们发现，通过 FIB 辐射形成的硅悬空键会还原 Au (III) 离子并引发金的成核。在这里，我们重点关注成长阶段。对黄金生长量的定量估计表明，硅悬键仅解释了黄金总量的一小部分。因此，生长机制不同于成核机制。在生长阶段，硅/金界面通过金成核形成后不久，界面附近晶体硅中的电子通过界面和生长的金还原金 (III) 离子。该机制与费米能级（电子的化学势）一致，费米能级按照硅>金>孤立形式的HAuCl 4 溶液的顺序降低。两次暴露于相同和不同的 HAuCl 4 溶液中显示的结果支持该机制，并允许进一步控制金形态。
We describe and experimentally verify the mechanism of area-selective electroless deposition of gold nanostructures at interfaces between locally induced naked silicon surfaces and pure HAuCl 4 solution. We previously demonstrated that gold nanostructures selectively grow on focused ion beam (FIB)-irradiated areas of a silicon substrate when the substrate is exposed to pure HAuCl 4 solution. We revealed that silicon dangling bonds formed by FIB irradiation reduce Au (III) ions and initiate the nucleation of gold. Here, we focus on the growth stage. Quantitative estimate of the amount of gold grown reveals that silicon dangling bonds explain only a fraction of the total amount of gold. Thus, the growth mechanism is different from the nucleation mechanism. In the growth stage, soon after silicon/gold interfaces form via gold nucleation, electrons in the crystalline silicon near the interfaces reduce Au (III) ions through the interfaces and the growing gold. This mechanism is consistent with the Fermi level (chemical potential of electrons), which decreases in the order silicon> gold> HAuCl 4 solution in the isolated form. Double exposure to the same and different HAuCl 4 solutions shows the results that support the mechanism, and allows further control of gold morphology.