With the advancements in the controlled growth of single-wall carbon nanotubes and modern lithographic techniques, gated 3-terminal carbon nanotube field-effect transistors have added to the possibilities of ultra large-scale integration in nano-electronics. It has also opened up the scope for very exciting fundamental research in the field of low dimensional electronic transport properties.

However, gate-modulated transport in single-wall carbon nanotubes are known to show significant hysteresis in their transfer characteristics, which stand in the way of accurate estimates of device properties, as well as the predictable performance of the devices. The origin of this hysteresis is generally attributed to the movement of mobile charges/ions in the presence of a trapping/de-trapping mechanism inherently present in the surrounding dielectric layer, as in conventional silicon MOSFETs.

From an extensive study of the temperature dependence of the hysteresis behavior, we establish an alternate mechanism, where the screening charges are injected from the nanotube itself into the surrounding dielectric. Any detailed trapping/de-trapping mechanism does not appear to play a significant role, and the experimental results can be simply explained in terms of a capacitive charging of the surrounding dielectric due to the charge injection. On the basis of these results, we present a simple yet effective model to understand and analyze this phenomenon, where the charge injection and its subsequent redistribution into the surrounding dielectric have been modeled as a series RC circuit. We next present a series of experiments with gated three-terminal s-SWNT devices, and also use this model to fit previously published data by other groups. The combination of theory and experiment serve to provide an in-depth picture of the parameters, which play a crucial role in modifying the transfer characteristics in s-SWNT devices under different experimental conditions. In particular, it helps to understand the changes in the position, magnitude and shape of the transfer characteristic curves as commonly seen in literature.

In single-wall carbon nanotubes (SWNTs), motion of electrons is confined in the 1D-like system so that many unique physical phenomena can occur even at room temperature.

Negative differential conductance (NDC) is observed in a bundle of SWNTs at room temperature. We find that the peak-to-valley current ratio is about 2 and the peak voltage gradually shifts from 9.2V to 7.8V with sweeping a gate voltage from 6V to -6V. It is noticed that the significant NDC is associated with a "burning-off" T process, in which the metallic SWNTs in the bundle were burnt off and the semiconducting SWNTs are left behind.

We suggest that two energy barriers are created on the SWNT bundle during the burning-off process. A quantum well is formed if the barriers are very close to each other so that hole energy in the well is quantized. The observed NDC is believed to be associated with hole resonance tunneling through the double barriers once the hole energy level is aligned with the discrete electronic energy levels between the barriers.

Thin solid films of fullerene-like (FL) compounds attract a growing interest due to their mechanical resiliency. The incorporation of N atoms at carbon sites in graphene planes is known to promote pentagon formation and cross-linking in FL-CNx (0x as an interesting material for thin film applications.

Being of higher reactivity than N and having a larger covalent radius, P causes stronger bending and higher linkage of the basal planes than for CN_x. This would imply a material with high compliance and low plasticity, eventually stronger than CN_x. Here, we present results from a first-principles calculation study to show that tetragons in layers are energetically favoured, which is not the case for CN_x. Lower content of P in CP_x compared to N in CN_x causes higher layer curvature and more cross- and inter-linkage sites. Significantly larger diversity of stable precursor species also exist for CP_x growth from the vapour phase compared to the CN_x case. Precursors can be both pure P clusters and CnPm (n,m≤3) structures, dominated by tetragons and hexagons. In CP_x pentagons are less favourable than in CNx. At high group 15 -element concentrations in the deposition flux, surface segregation will limit the amount of structurally incorporated P or N.

Results from initial CP_x thin film deposition experiments using DC magnetron sputtering in a HV system is also presented. Structural and tribological characteristics of CP_x and CN_x thin films will be compared.