Synthesis and functional materials properties of 2-D arranged SiC and SiCN materials

在纳米尺度上以棒状结构排列的材料在大面积的二维结构中提供了独特的新性质。一维纳米材料对于研究与尺寸相关的化学、物理和力学现象具有重要意义。这些材料的性能敏感地依赖于它们的几何形状和配置，可以包括管状结构(单壁或多壁管)、实心圆柱形纳米线或同轴结构。我们建议通过分子前驱体/模板相结合的方法来合成和排列SiCN和碳化硅纳米棒。我们的纳米棒合成可以(I)通过基于分子的溶液路线进行，该路线将前体分子结合到纳米多孔模板主体材料中，随后进行一系列热解步骤。或者(Ii)合成将采用在纳米孔模板结构内形成纳米棒的气相分子路线。所使用的氧化物模板是具有高度取向的六方纳米孔排列的可调孔径(10-100 nm)的独立薄膜。这种独特的方法提供了在更大的区域(高达cm2)上稳定棒状阵列的可能性，通过使用模板作为定向的预组织支架，以获得嵌入的和独立的(在模板溶解后)定向的碳化硅和氮化硅纳米棒。这种新型纳米棒的结构和功能特性有望应用于(I)用于机械纳米光刻工艺的压花印章以及(Ii)用于电子场发射的高深宽比发射器。这些功能特性也将在我们的项目中进行研究。

Materials which are structured on the nanoscale in rod-like configurations offer unique new properties when arranged in two dimensional structures over large areas. One dimensional nanomaterials are of fundamental importance to the study of size-dependent chemical, physical and mechanical phenomena. The properties of such materials sensitively depend on their geometrical shape and configuration, which can include tubular structures (single or multi-walled tubes), solid cylindric nanowires or coaxial constructions. We are proposing to synthesize and arrange SiCN and SiC nanorods through a combined molecular precursor-based / template approach. Our nanorod synthesis proceeds either (i) via a molecular-based solution route, which incorporates the precursor molecules into nanoporous template host materials, followed by a sequence of pyrolysing steps. Alternatively (ii) the synthesis will employ a gas pase molecular route which forms the nanorods inside a nanoporous template structure. The oxide based templates used are available as free-standing films with tunable pore size diameter (10 - 100 nm) with a highly oriented hexagonal nanoporous arrangement. This unique approach offers the possibility of stabilizing rod-like arrays over larger areas (up to cm2) by using the template as a oriented preorganized scaffold for obtaining embedded as well as free-standing (after template dissolution) oriented SiC and SiCN nanorods. Structural and functional properties of the new nanorod arrangements promise potential to envisaged applications as (i) embossing stamps for mechanical nanolithography processes as well as (ii) high aspect ratio emitters for electronic field emission. Such functional properties will also be studied in our project.