Technologies

Silicon nanowires (SiNWs) are 1D structures with diameter ranging from few tens to hundreds of nanometers and length varying from few tens of nanometers to millimiters. SiNWs are fabricated in the labs of the IMM-CNR, Rome Unit,  by using bottom-up technologies such as plasma enhanced chemical vapor deposition (PECVD) at low growth temperature ((≤350°C), allowing the use of plastic and glassy substrates. Their electrical properties can be tuned by controlling the p/n doping during the growth.

We propose an optical technique for the fast check of the presence, on the exposed surfaces of persons and objects, of explosives and their precursors, or drugs, or in general materials which are not allowed in restricted environments: airports, courts, places of worship, etc. The technique yields bi-dimensional pictures, with exposure time of < 1 sec, reporting the target substances, and their locations and quantities. The technique already provided laboratory preliminary results, to be completed, and fully validated for sensitivity and selectivity.

The proposed technology takes advantages of the huge potentialities of the gellan gum microgels in the preservation of cultural heritage. Microgels are polymeric gels particles with the micro and nanoscale size, whose soft nature is due to the presence of the aqueous solvent inside the particle. For their small size, they can easily diffuse in the environment and penetrate in the porous structure of paper and wood to act as cleaner agent.

Mirrors for space applications, besides featuring suitable optical properties, should be light, resistant to mechanical stresses, and unsensitive to light-shadow thermal cycling. The standard optical materials easily fulfill optical and thermal requirements, but are fragile, and the mirrors must be thick (typically 1/6 of the diameter). For this reason they are heavy, and the only available solution is to lighten them, by removing material from the back side, still preserving the necessary mechanical robustness and optical quality.

Chemical solution deposition of metal-organic precursors have favoured the research and development of thin films of simple and complex oxides such as Pb(Zr,Ti)O3, and Al2O3, up to their industrial application in pyroelectric and capacitor devices. Deposition methods used are spin-on and dip-coating. The advantages of the techniques are:

(i) low cost of equipment and chemicals

(ii) large area deposition

(iii) low crystallisation temperatures

The instrumentation is based on the electrical resistivity tomography (ERT) which is a non-invasive geophysical technology used to obtain information on anomalous bodies possibly present in the subsoil. The theoretical basis lies in the different electrical properties of the lithotypes present in the subsoil.

The proposed technology deals with the development of active SERS (Surface Enhanced Raman Scattering) substrates ad hoc designed for diagnostics of cultural heritage. The substrates are prepared starting from common commercial 'polishing film' sheets (lapping optical fibers) showing an intrinsic roughness (48- 1000 nm) that favors the SERS effect. A pattern of silver or gold nanoparticles are deposited on these films through Pulsed Laser Deposition (PLD).

The instrument which is under development is a non-conventional portable Raman spectrometer. Raman spectrometers provide the molecular composition of the material surfaces, essential for their identification. The instrument peculiarity relies in the simultaneous acquisition of Raman spectra at imaged position and at different micrometric distances (offset) from the laser illumination area.

The proposing team that works at CNR ISTEC has recently patented a technology for the production of the Smart Polycrystals (SP), i.e. transparent YAG-based ceramic polycrystals (Y₃Al₅O₁₂) variably doped with rare earths ions and transition metals ions. The SPs solve the problem of the reduction of the efficiency in the solid state laser systems caused by the inhomogeneous heating of the single crystals during the emission process.