Submitted Abstract
The capability of shaping, manipulating and assembling the materials at the nanoscales enables the development of unprecedented functional surfaces and devices, exploiting the peculiar properties of nanosized systems. In this framework, cluster-assembled films show a unique structure where the nanometric “building blocks” maintain their original characteristics within a 3D nanoporous network, which favors the interaction between the material and the surrounding environment.Cluster Beam Deposition (CBD) is currently considered as one of the most promising approaches for the direct integration of cluster-assembled nanoporous functional films in devices, however, various unsolved issues still exist. This especially regards: the control of the cluster size distribution, the chemical/structural composition of multi-element aggregates, and the electrical conduction features of the cluster-assembled 3D nanoporous network.CLASMARTS aims to the development and fine-tuning of cluster-assembled nanoporous functional films by addressing the issues above, and identifies the field of miniaturized gas sensing for pervasive monitoring of air conditions as the applicative perspective that may take advantage of project’s outcomes.Gas-phase cluster aggregation process will be studied in order to understand the key parameters determining the cluster size distribution and its role on film nanoporosity. The production of multi-element clusters, composed by a catalytic metal and a transition-metal oxide, will be addressed, aiming to understand and control intra-particle phase segregation phenomena. The goal is to drive the formation of a nanocomposite structure where a transition-metal oxide core nanoparticle supports the catalytic metal on its surface. The electrical conduction in cluster-assembled films will be investigated in-situ, during film growth, aiming to identify the percolative conduction threshold, to characterize the resistivity vs. thickness relationship, and to assess the role of post-deposition oxidation. For the above, a prototype system for CBD will be developed on purpose.The impact of project outcomes will mostly regard the knowledge of gas-phase synthesis of atomic aggregates and nanoparticles, of the growth dynamics of cluster-assembled nanoporous 3D networks and of their electrical conduction properties. In a perspective scenario beyond the purposes of the project, the capability to tune the synthesis of catalyst-decorated oxide nanoparticles assembled in a nanoporous 3D network will pave the way to the development of highly miniaturized gas sensors with enhanced sensitivity and response dynamics, and reduced operating temperature.