Assembly of metal nanoparticles into nanogaps
Assembly of metal nanoparticles into nanogaps
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DOI：
10.1002/smll.200600334
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发表时间：
2007-03-01
期刊：
影响因子：
13.3
通讯作者：
Stellacci, Francesco
中科院分区：
文献类型：
--
作者：
Barsotti, Robert J., Jr.;Vahey, Michael D.;Stellacci, Francesco
将纳米颗粒和纳米级材料定向组装到表面的特定位置是纳米技术的主要挑战之一。在这里，我们提出了一个简单的和可扩展的方法和模型的组装纳米粒子之间的电引线。金纳米粒子，直径为20 nm，组装内的电气间隙范围从15至150 nm的使用正交流介电电泳。在这种方法中，交流电用于产生电场梯度，该电场梯度吸引用于产生电势的两个引线之间的颗粒。当介电泳力超过热和静电力时实现组装;存在于差距中的锚定分子的使用提高了最终组装的稳定性。我们用实验和理论证明了纳米颗粒在差距内的组装是由所施加的电压和差距的尺寸控制的。实验证据和建模表明，一个间隙大小依赖的阈值电压必须克服之前实现粒子组装。组装结果作为频率和时间的函数。展示了间隙中少于10个孤立颗粒的组装。初步的电特性表明，组装粒子的稳定电导可以实现。
The directed assembly of nanoparticles and nanoscale materials onto specific locations of a surface is one of the major challenges in nanotechnology. Here we present a simple and scalable method and model for the assembly of nanoparticles in between electrical leads. Gold nanoparticles, 20 nm in diameter, were assembled inside electrical gaps ranging from 15 to 150 nm with the use of positive ac dielectrophoresis. In this method, an alternating current is used to create a gradient of electrical field that attracts particles in between the two leads used to create the potential. Assembly is achieved when dielectrophoretic forces exceed thermal and electrostatic forces; the use of anchoring molecules, present in the gap, improves the final assembly stability. We demonstrate with both experiment and theory that nanoparticle assembly inside the gap is controlled by the applied voltage and the gap size. Experimental evidence and modeling suggest that a gap-size-dependent threshold voltage must be overcome before particle assembly is realized. Assembly results as a function of frequency and time are also presented. Assembly of fewer than 10 isolated particles in a gap is demonstrated. Preliminary electrical characterization reveals that stable conductance of the assembled particles can be achieved.