Periodic Reporting for period 2 - NARCISO (NAtuRal instability of semiConductors thIn SOlid films for sensing and photonic applications)
Okres sprawozdawczy: 2020-03-01 do 2023-01-31
2) Phase field simulations have been systematically exploited to model, analyse, assess and predict the features of dewetted structures. Anisotropic-phase field allowed to precisely predict the final morphology of SiGe nanostructures including the effect of preferential crystallographic directions for adatoms surface diffusion (e.g. faceting, final shape). We are now capable to fine tune the initial shape of the patch and its orientation with respect to the crystallographic directions targeting a specific final state of dewetting. This modelling approach is also an effective tool to predict the disordered hyperuniform character of a final structure obtained via SiGe dewetting, helping in targeting specific features and performance of a device. Other achievements related to PF simulations include the modelling of fluid-dynamics in disordered hyperunifom structures addressing the case of swimming (motile and non-motile) bacteria. The simulations have been used to benchmark the relevant aspects of fluid dynamics in porous materials, helping the understanding of the role of dead-end pores in bacteria colonization of porous media.
3) The disordered hyperuniform morphologies were exploited to fabricate micro-fluidic channels to study the transport of colloids and colonization strategies of bacteria. This study allowed to explore fundamental phenomena related to particles filtering, trapping, bacterial motility, chemotaxis and colonization of porous media with a particular focus on the role of dead-end pores.
4) NARCISO has been intensively working on NIL of metal oxides (MOx-NIL) by developing new materials and demonstrating new features and applicability of original structures. As an example of application of MOx-NIL we reported the fabrication of anti-reflection coatings (ARCs) made of SiO2 atop glass and fused silica wafers.
5) In NARCISO we developed a new hyper-spectral imaging method that allows to extract information on the angular pattern of specific Mie resonances in a single measurement and avoiding the use of polarisers. About the disordered hyperuniform photonic devices, we mention the important result of engineered photonic crystals to demonstrate the formation of high quality random modes and strong light localization at near infrared frequency. The transition from localization to diffusive light transport within a single disordered hyperunifom system was demonstrated by exploiting near-field mode imaging.
-A last advance in solid state dewetting was the fabrication of Ge islands by using a conventional rapid thermal processor instead of an ultra-high vacuum chamber (in a molecular beam epitaxy reactor).
-The dewetted SiGe architectures with spinodal like features were exploited as a model material to reproduce a porous medium to investigate the role of transmitting channels, where a fluid can flow, and dead-end pores, where the fluid does not flow. Our finding is important to develop new strategies for water filtering and detection of bacteria in a faster and more efficient way.
- NARCISO provided the ground to create SOLNIL, a spin-off of AMU at work on sol-gel coatings and nano-imprint lithography. Beyond the results mentioned in this report, all the knowledge produced in NARCISO can be exploited by SOLNIL for micro-fluidic (e.g. for DNA sequencing) and photonic devices (e.g. for anti-reflection coatings, photonic metasurfaces, meta-lenses). They are both produced by SOLNIL that has already attracted several customers that are paying to develop specific materials and devices deigns. Beyond these customers, SOLNIL is currently undergoing a fund-rising (pre-seed) that should be finalised by April 2023.