Antioxidant coatings and spot size reduction on porous silicon and characterizing luminophore doped xerogels and germanium ultra-thin films.

摘要

Characterization is fundamental in new materials synthesis and research, sensors, and optical coatings. This dissertation focuses on characterizing our porous Si (pSi) samples, luminophore doped xerogel based O2 sensing platforms, and ultra-thin Ge optical films. Because our pSi electrochemical etching parameters are unique, we have characterized our pSi porosity, thickness, depth dependent morphology, topography, chemistry, and photoluminescence (PL) based on changes in anodization time. We then used our pSi wafers as a platform for pin-printing and hydrosilylating pSi microarrays. We reduced pin-printed spot sizes by increasing pSi porosity and decreasing reagent viscosity and pin diameter in accordance with the molecular-kinetic theory and Darcy's Law for unidimensional imbibition. We finally coated our "as prepared" pSi samples with various antioxidants (AO) and established a relationship between AO strength, oxidation potential, AO binding to pSi, reduction in PL degradation, and protection against O3 oxidation. Next, we ink-jet printed [Ru(dpp)3]2+ doped hybrid xerogels onto clean glass and compared Stern-Volmer constants, excited state lifetimes, and bimolecular quenching rate constants between spin-coating, pin-printing, and ink-jet printing techniques. Finally, we characterized our ultra-thin Ge film topography and chemistry by using co-localized atomic force microscopy and Raman spectroscopic mapping.