Ermanno Di Zitti

Langmuir films of thiolated gold nanoparticles transferred onto functionalized substrate: 2-D local organization

Abstract The aim of this work is to fabricate ordered arrays of thiolated gold nanoparticles grafted through electrically conductive molecular tethers onto gold electrodes. Dodecanethiol-capped gold nanoparticles were synthesized in a two-phase liquid–liquid system. Cluster size selection by the vapor transfer technique was repeatedly performed in order to obtain a narrow nanoparticle core diameter distribution that peaked around 2 nm. Transmission electron microscopy (TEM) imaging of drop cast films prepared onto carbon-coated grids allowed us to assess the performance of each fractionalization process step and the corresponding particle aggregation behavior. A 1,4-benzenedimethanethiol self-assembled film onto hetero-epitaxial gold on mica has been chosen as a grafting substrate for size-selected gold nanocluster films. Using an air, room temperature scanning tunneling microscopy (STM), the behavior of drop cast and Langmuir nanocluster films onto this substrate was investigated. Better results in terms of adhesion and 2-D aggregation were obtained in the case of Langmuir films. This performance has been further enhanced by application of the multi-step creep method during the Langmuir film making.

Investigating Schottky Barriers Effects in Carbon Nanotube FETs

The paper addresses the issue of Schottky barrier effects in carbon Nanotube field effect transistors and outlines some solutions to tackle such problem. Microfabricated test patterns have been designed to allow the deposition in a controlled way of single wall nanotubes between different couples of source and drain electrodes in a backgate device architecture. Current‐voltage characteristics depending on the back gate applied voltage have been recorded and briefly discussed. Through a proper exploitation of ad‐hoc developed contact arrays for CNFET fabrication, a strategy for the direct measurement of metal‐CN and CN‐CN junction characteristics has been described.

A Serious Game Architecture for Green Mobility

Good driving behavior is a significant factor for road safety and green mobility. A countermeasure to overcome the coarse driving behavior and a methodology to captivate optimal driving traits are discussed in this work. For which, the serious games concept was exploited to improvise the driver performance by deploying diversified game logics (scores, incentives and live game for performance evolution) on a smartphone-based user interface. The application was tested in ASTA ZERO (Active Safety Test Area) in Sweden. The tests comprised of variations (good and bad driving behavior) in driving pattern for analyzing the impact of the application on the driver performance.

Characterization of a cellular array of dipoles for molecular information processing

A physical system consisting of a lipid monolayer surrounded by a set of electrodes is defined and proposed as a plausible example of a molecular circuit for information processing. The lipid monolayer is characterized as a cellular array of electric dipoles, where each dipole lying on the monolayer plane represents the head of a lipid molecule. Each dipole experiences the effects of the electric field generated by both the surrounding dipoles and the electrodes. The electrodes’ contribution to the electric field is calculated through a proper discretization of their charge densities. According to this model the dipoles of the cellular array play the role of neurodes whose state is described by the dipole orientations on the plane, and a cellular automation can be defined once the orientation values have been properly discretized. The electrodes act as input‐ and output‐signal sources. it is shown that the simple system considered here, i.e., a two‐port system, is characterized by a nonlinear voltage tran...

Hybrid Nanostructures: Organic Interconnections and Device Applications

Silicon technology is rapidly progressing toward device sizes in the range of 10 nm. The evolution rate of silicon technology in next decades will require the use of new materials and processes to develop revolutionary CMOS devices. Organic nanostructures onto semiconductors or metals may provide interesting solutions to address the technological issues of nanoscale devices. In particular, technologies and devices based on organic nanostructures such as carbon nanotubes, semiconductor or metallic nanoparticles, DNA-templated nanowires may supply solutions for on-chip interconnections. The aim of this work is to present recent results on hybrid nanostructures based on gold nanoparticles stabilized by organic coating. Particular emphasis is devoted to the problem of the interconnections at the nanoscale. The resulting hybrid devices are suitable to develop single electron transistors and memories

Fabrication of Field Effect Transistors based on carbon nanotubes made by LASER ablation

We report results obtained performing the fabrication of a back gate Field Effect Transistor that uses a rope of single wall nanotubes as channel. Nanotubes were made using the LASER ablation technique and they were characterized using micro‐RAMAN spectroscopy, SEM and AFM imaging. A self‐assembly method based on a high frequency electric field was used to direct the placement of nanotube ropes between source and drain gold electrodes made by low cost standard microlithographic techniques. Measurements of the electrical transport in the nanotube ropes depending on the applied gate voltage are reported.

Scanning tunneling microscopy imaging of organic layers on graphite

Organic monolayers of dotriacontane and tetracosanoic acid physisorbed on graphite have been studied by scanning tunneling microscopy at the liquid-solid interface. A high degree of two-dimensional ordering appeared for both the organic compounds observed : the molecules were arranged on graphite in stripelike lamellae of various shape and length. Experimental conditions for high contrast imaging are discussed.