The development of experimental techniques capable of manipulation and analysis at the nanoscale has determined in the last years the enormous fortune of nanotechnology. One of the most fascinating aspects is the manifestation in realistic systems of theoretically predicted (but often unexpected) quantum effects that lead to remarkable and unusual properties of matter at the 10-100 nm scale. In particular, the technology for the fabrication of organic nanostructures designed to become microelectronic devices is now mature, and the concepts governing the growth and stability of nano-derivatives of molecular crystals are now accessible. The range of forecasted applications is broad: catalysis, solar cells, nanosensors, lasers, device miniaturization, etc. The choice of p-conjugated molecules as building blocks for such organic nanostructures is central in the definition of this emerging new field and has clear advantages: ease of synthesis at low cost and big scale, processing in solution and possibility to control the properties of the devices by molecular design. In our laboratory at Empa a methodology was recently developed to fabricate single-crystalline 1D nanostructures with high density, quality and purity. The growth method is based on a plasma vapor deposition process of organic molecules on tailored-roughness substrate surfaces. Such substrate-supported nanowires are ideal systems for fundamental studies such as: understanding of complex self-assembly mechanisms for organic molecules into crystalline structures, elucidating transport mechanisms, addressing the role of nanoscale domains in microstructures, defining of the relationship between molecular/crystalline structure and corresponding electronic properties. The generalization of this growth methodology to different molecules provides a straightforward way to study the relation between the chemical structure of the molecules and the final morphology and structure of the wires. atomistic simulations, in connection to the experiments that are being conducted in our laboratory. ab initio The aim of the present project is to understand the structural and electronic properties of selected nanowires belonging to different molecular precursors by means of The project will be focused towards two main goals: - The investigation of the geometric and electronic properties of ideal models of nanowires based on Cu-phtalocyanines and Co-phtalocyanines.
- Understanding of the transport properties of the nanowires
The successful outcome of the present project will represent a considerable step forward in the understanding of the electronic properties of molecular nanowires. Although transport theories are developed since several years, due to their complexity in relation to systems such as molecular nanowires, there are no detailed investigations of the transport properties of similar systems. The results obtained within our project will represent a step forward in the understanding of complex transport phenomena. Moreover, the collaboration with developers of transport theory codes will allow to tune and develop future instruments, more suitable for application in direct connection with experiments.
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