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

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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.