Field supported in-situ growth and transport properties of functionalised carbon nanotubes

碳纳米管是一种具有独特结构和可调电子性质的一维理想材料，在基础研究和技术应用中具有重要意义，近年来引起了人们的极大兴趣。对于基于纳米管的器件中的传输，需要解决几个重要的问题：即，控制纳米管的类型，详细了解其作为功能化的电子特性，接触和电荷载流子注入。在目前的项目中，这些问题将通过在一个特制的反应器中通过化学气相沉积（CVD）在预定衬底上原位生长功能化碳纳米管来解决，该反应器允许由电场和磁场梯度支持的点对点生长。样品的形态和纳米管的类型将利用诸如扫描力和电子显微镜以及共振增强拉曼光谱、扫描探针显微镜和光学光谱的工具来表征。包含半导体管的器件将被研究作为栅极电压的函数，而对于基于金属管和铁磁电极的器件，自旋注入和自旋相关的输运将被分析作为磁场的函数。此外，通过掺杂物（例如FeCl 3，K，溶剂和气体）后功能化对传输特性和器件性能的影响将进行分析，特别是关于它们在生物学，化学和工业过程监测中的传感器应用的潜力。

Carbon nanotubes have aroused great exitement in the recent years since they are ideal one dimensional objects with unique structural and tunable electronic properties which are relevant for both, basic research and technological applications. For transport in nanotube based devices several important problems need to be solved: i.e. control of the type of nanotube, a detailed understanding of its electronic properties as function of functionalization, the contacting, and the charge carrier injection. In the current project these points will be addressed using in situ growth of functionalised carbon nanotubes on predifined substrates by chemical vapor deposition (CVD) in a purpose built reactor allowing point to point growth supported by electrical and magnetic field gradients. The morphology of the sample and the type of nanotube will be characterized utilizing tools such as scanning force and electron microscopy as well as, resonance enhanced Raman spectroscopy, scanning probe microscopy, and optical spectroscopy. Devices containing semiconducting tubes will be studied as a function of gate voltage whereas for devices based an metallic tubes and ferromagnetic electrodes the spin injection and the spin dependent transport will be analysed as a function of the magnetic field. In addition, the influence of post functionalisation by dopands (e.g. FeCl3, K, solvants and gases) on the transport properties and the device performance will be analysed especially regarding their potential for sensor applications in biology, chemistry and process monitoring in industry.