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

当在大面积上以二维结构排列时，在纳米级上以棒状构造结构化的材料提供独特的新性质。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。这些材料的性质敏感地取决于它们的几何形状和构造，其可以包括管状结构（单壁或多壁管）、实心圆柱形纳米线或同轴构造。我们建议通过结合分子生物学/模板方法合成和排列SiCN和SiC纳米棒。我们的纳米棒合成通过（i）基于分子的溶液路线进行，其将前体分子并入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）合成将采用气相分子路线，其在纳米多孔模板结构内形成纳米棒。所使用的基于氧化物的模板可用作具有可调孔径直径（10 - 100 nm）的独立膜，其具有高度取向的六方纳米多孔排列。这种独特的方法提供了通过使用模板作为定向的预组织支架来在更大的面积（高达cm 2）上稳定棒状阵列的可能性，用于获得嵌入的以及独立的（模板溶解后）定向的SiC和SiCN纳米棒。新的纳米棒排列的结构和功能特性承诺了作为（i）用于机械纳米光刻工艺的压印印模以及（ii）用于电子场发射的高纵横比发射器的设想应用的潜力。我们的项目也将研究这些功能特性。

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.