Fabrication and characterization of functional nanowire and tube based devices

最近，我们发现在金属蒸发后，过渡金属二硫属化合物（TMDCs）的平面上，纳米线（小至8nm）的扩展网络（cm级）自组织。初步结果表明，现在可以用类似的方法在绝缘聚合物衬底上获得金属纳米线。通过在聚合物表面使用不同的粘附系数，在预应变基板上采用传统的CVD工艺制备出连续型和“断线”型纳米线。此外，它们可以在各种几何形状中以极好的精度对齐，从单个孤立的电线到平行和垂直相交网络阵列。这种新型纳米线的另一个优点是，除了高度可控和在厘米大小的基板上快速生产之外，它们是在表面形成的。由于这些纳米线只是部分嵌入，因此线的一侧由衬底表面机械支撑，而另一侧则很容易接近，不仅可用于功能化和直接应用，如气体传感器，还可用于进一步的三维结构。最后，我们发现在聚合物中金属化原纤维可以形成连接良好的金属纳米管。我们建议系统地研究这种生产纳米线和纳米管的新方法。我们打算探索哪种材料组合能提供最佳条件来产生这些排列的纳米结构，并找到最适合应用的组合。这可以通过了解材料特性方面的潜在生长机制的细节来实现，包括扩散长度、粘附系数或所应用聚合物材料的薄膜特征。基尔大学多组分材料主席在金属-聚合物界面领域以及纳米线研究方面有着长期的专业知识。由于该项目进一步研究了纳米线与技术相关材料的受控合成，我们相信我们的新方法可以为schwerpunktprogram的进展做出重大贡献：“Nanodrähte und Nanoröhren: von kontrollierter Synthese zur Funktion”。

Recently, we have discovered that extended networks (cm-scale) of nanowires (as small as 8nm) self-organize on the flat surfaces of transition metal dichalcogenides (TMDCs) after metal evaporation. The preliminary results show that it is now possible to obtain, with a similar approach, metal nanowires on insulating polymer substrates. Fabricated by a conventional CVD process on pre-strained substrates by using different sticking coefficients on polymer surfaces, continuous as well as "dashed" nanowires form. Furthermore, they can be aligned with excellent precision in various geometries, ranging from single isolated wires to arrays of parallel and perpendicular intersecting networks. A further advantage of these new class of nanowires, other than the high amount of control and a rapid production on cm-sized substrates, is that they form on the surface. Because theses nanowires are only partially em-bedded, one side of the wire is mechanically supported by the substrate surface, while the other side is readily accessible, not only for functionalization and direct applications such as gas sen-sors but also to enable further three-dimensional structuring. Lastly, we have discovered that the metallization fibrils in polymer crazes lead to well-connected metal nanotubes. We propose to study systematically this novel approach for the production of nanowires and nanotubes. We intent to explore which material combinations allow the best conditions to generate these aligned nanostructures and find the combinations best suitable for applications. This can be done by understanding the details of the underlying growth mechanisms in terms of material properties including diffusion length, sticking coefficients, or thin film features of the applied polymer materials. The Chair for Muticomponent Materials at the University of Kiel has long-standing expertise in the field of metal-polymer interfaces and as well as in nanowire research. Since this project further investigates the controlled syntheses of nanowires with technologi-cally relevant materials, we believe that our new approach can contribute significantly to the progress in the Schwerpunktprogramm: "Nanodrähte und Nanoröhren: von kontrollierter Synthese zur Funktion".