Exploiting porous silicon technology for photonic applications: from bioresorbable sensors to monolithic lasers

In this thesis work, nanostructured porous silicon has been used in a variety of photonic applications. First of all, a thorough literature review on bioresorbable electronics is offered, analyzing passive components, power sources, physical and chemical sensors, and optical devices. Then a bioresorbable optical pH sensor with possible application in skin wound monitoring is presented, leveraging porous silicon as structural material for layer-by-layer nanoassembly of polyelectrolyte functionalized with fluorescent moyeties. Device fluorescence is demonstrated to be pH-dependent in buffered solutions and simulated plasma, in flow cell and inserted under artificial skin foil. Finally, a simple method to estimate theoretical reflectance and transmittance spectra of arbitrary layered dielectric structures is reported, and its application versatility in various porous silicon photonic crystal (namely, interferometers, distributed Bragg reflectors (DBRs), and resonant microcavities) modeling is shown.