Seminar Announcement: Monica Bollani

Data pubblicazione: 12-ott-2020

Announcement

Monday, 19 October 2020, 15:00

Sala Grande Palazzina B via alla Cascata 56/C

"Solid-state dewetting of Si(Ge)-based complex nano-architectures and their applications in photonics and bio/chemical sensing"

Monica Bollani

Institute for Photonics and Nanotechnologies, CNR,

Laboratorio LNESS,

via Anzani 42,

22100 Como, Italy

Abstract

Silicon-based nanocrystals represent a promising resource both for next generation electronic devices and for nano-photonics applications but require precise size, shape and position control. However, owing to their large surface-area-to-volume ratio, thin semiconductor solid films are often unstable upon annealing. Under the action of surface diffusion, the film breaks eventually forming isolated islands. This is one of the main factors impeding the use of ultra-thin silicon films on insulators (UT-SOI) for the further miniaturization of electronic components. Today we propose to exploit the natural instability of thin solid films (solid state dewetting of silicon and germanium) to form complex patterns and nano-architectures (e.g. monocrystalline atomically-smooth structures, disordered hyperuniform metamaterials) that cannot be implemented with conventional methods. These patterns are used as: i) epitaxial platforms for the growth of light-emitting III-V compounds; ii) hard-masters for nano-imprint lithography of metal oxides (e.g. TiO) deposited via sol-gel dip-coating (soft-NIL) and printed on arbitrary substrates, with tunable chemical and physical properties (e.g. composition, porosity, wettability). Methods and structures are optimized towards their exploitation in two main domains of application: 1) photonic devices (e.g. anti-reflection coatings, colour-filters, random lasers, quantum emitters) and 2) micro-fluidic devices for bio/chemical sensing and water filtering. The research activity is performed in the framework of the EU H2020 FET-OPEN NARCISO (Grant No. 828890)