Tunable Ultra-high Aspect Ratio Nanorod Architectures grown on Porous Substrate via Electromigration.
Tunable Ultra-high Aspect Ratio Nanorod Architectures grown on Porous Substrate via Electromigration.
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DOI：
10.1038/srep22272
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发表时间：
2016-02-29
影响因子：
4.6
通讯作者：
Mannan SH
中科院分区：
文献类型：
--
作者：
Mansourian A;Paknejad SA;Wen Q;Vizcay-Barrena G;Fleck RA;Zayats AV;Mannan SH
多孔性和电迁移之间的相互作用可用于操纵原子，从而导致纳米级结构的大规模制造。电迁移通常导致原子的积累，伴随着阳极处的突起和在阴极处引起空隙的原子耗尽。在这里，我们表明，在多孔介质中的原子沉积和耗尽的模式被改变，使原子积累发生在整个表面，而不仅仅是在阳极。这种效应是由电流引起的原子漂移和晶粒间收缩处强烈焦耳加热引起的局部温度梯度之间的相互作用解释的。利用这种效应，多孔银基底用于使用108 A/m2量级的电流密度大量生产具有大于200的非常高的纵横比的独立式银纳米棒。这种简单的方法导致可重复形成的形状纳米棒，其密度和长度的独立控制。因此，可以原位形成高质量单晶纳米棒的复杂图案，与用于等离子体、能量存储和传感应用的纳米棒形成的竞争方法相比具有显著的优势。
The interplay between porosity and electromigration can be used to manipulate atoms resulting in mass fabrication of nanoscale structures. Electromigration usually results in the accumulation of atoms accompanied by protrusions at the anode and atomic depletion causing voids at the cathode. Here we show that in porous media the pattern of atomic deposition and depletion is altered such that atomic accumulation occurs over the whole surface and not just at the anode. The effect is explained by the interaction between atomic drift due to electric current and local temperature gradients resulting from intense Joule heating at constrictions between grains. Utilizing this effect, a porous silver substrate is used to mass produce free-standing silver nanorods with very high aspect ratios of more than 200 using current densities of the order of 108 A/m2. This simple method results in reproducible formation of shaped nanorods, with independent control over their density and length. Consequently, complex patterns of high quality single crystal nanorods can be formed in-situ with significant advantages over competing methods of nanorod formation for plasmonics, energy storage and sensing applications.