Porous silicon microcavities for sensing purposes: modeling and experimental results

On exposure at different chemical substances several physical quantities of porous silicon, such as reflectivity, photoluminescence, and electrical conductivity, change drastically. In particular, we have used porous silicon microcavities as chemical sensors, measuring resonant peak shifts in the reflectivity spectra due to capillary condensation of the vapor in the silicon pores. Understanding sensor behaviour depends on the dielectric function model and on the interaction mechanism assumed. With proper choices, we can also quantitatively characterize the Porous Silicon Microcavity sensing device features.