Optical study of polymer infiltration into porous Si based structures

Abstract

This work describes the infiltration of a polymeric solution into porous Si structures towards the fabrication of tunable photonic crystals (PC) and microcavities for photonics applications. The tunability is achieved by infiltrating the porous silicon based PCs by active organic materials, such as an emissive and nonlinear polymer called 2-methoxy-5-(2- ethylhexyloxy)-p-phenylenevinylene (namely MEH-PPV). This preliminary work shows the infiltration of this polymeric solution into PC based on macroporous Si structure as well as in microcavities based on multiple layers of microporous Si. The solidification of the polymer was obtained by the evaporation of the solvent. Various techniques of infiltration were studied to obtain an optimized filling of the pores. The infiltration was then characterized using photoluminescence measurements. Finally, we will report on the study of third harmonic generation (THG) in samples of porous silicon microcavity infiltrated with MEHPPV. The k-domain THG spectroscopy was applied and an increase of the THG intensity up to an order of magnitude was achieved for the filled microcavity.