By the use of a chemical vapour deposition technique a series of metal wires (W, Ta, Steel ) with differently shaped tips have been coated by arrays of single wall carbon nanotubes (SWNT). The field emission properties of the SWNT deposits have been measured by a home made apparatus working in medium vacuum (10<sup>-6</sup>- 10<sup>-7</sup> mbar) and the SWNT-coated wires have been used to fabricate tiny electron sources for X-ray tubes.
To check the efficiency of the nanotube coated wires for X-ray generation has, a prototype X-ray tube has been designed and fabricated. The X-ray tube works at pressures about 10<sup>-6</sup> mbar. The target ( Al film) is disposed on a hole in the stainless steel sheath: this configuration makes unnecessary the usual Be window and moreover allows us to use low accelerating potentials (< 6 kV).
The gas sensor based on carbon nanotubes are presently receiving considerable attention because of the outstanding
properties, such as faster response, higher sensitivity, lower operating temperature and robustness of the nanotubes in
comparison with the other types of sensing materials.
In the present research, we demonstrate detection of hydrogen at room temperature using a Quartz Crystal Nano-balance
(QCN) and as sensing material, Single-Walled Carbon Nanotubes (SWCNTs) dispersed in a polythiophene matrix. The
experimental determination of H<sub>2</sub> in H<sub>2</sub>/N<sub>2</sub> mixtures has been performed by using a counter frequency and observing the
frequency shifts induced in a quartz crystal resonator by H<sub>2</sub> adsorption and consequent mass variation of the active layer
deposited on the quartz.
The high sensitivity of the realized nano-balance allows us to observe mass variations up to few nanograms /Hertz and to
detect up to 1% of H<sub>2</sub>. The good sensing performances of the nanotube-based material make unnecessary the use of any
catalyst species for H<sub>2</sub> detection. Moreover this QCN device is able to work with good efficiency at 23 °C and 1 Atm.
The importance of nanocomposites materials such as carbon nanotubes-polymers composites for the efficient realization
of innovative solar cells based on organic as well hybrid organic-inorganic solar cells is more and more evident. We
present a study on the realization of dye sensitized solar cells (DSSC) and sublimation deposited solar cells, considering
the impact of using nanocomposite materials in the different sections composing the cells. We discuss the effect of using
poly-3,4-ethylene dioxythiophene/poly(styrene sulfonate) (PEDOT/PSS)-Carbon nanotube (CNT) blend as counterelectrode
in DSSC on the cell efficiency and fill factor, also considering DSSC structures where low cost, innovative
dyes are used. Nanocomposites can be used as solution processed or electropolimerized electrodes, where accurate
control of nanotube dispersion is obtained through specific chemical treatment of Carbon nanotubes solubility. The use
of Carbon based nanostructured material is also investigated in terms of their positive impact on the realization of
organic solar cells on flexible substrates.