The present paper reports the study of a porous silicon based microcavity
for a potential chemical sensing application using tris-(8-hydroxyquinoline) aluminum (Alq3) molecules. Porous silicon based
planar microcavity was first designed and fabricated using the
electrochemical etching technique. Photoluminescence emission of a single
porous silicon layer after immersion in an Alq3 solution was first
carried out in order to verify that the Alq3 molecules were bound to
the porous surface. A wide green band centered at 519 nm, typical of a
nano-structured Alq3 film, was observed. Reflectivity measurements of
the porous silicon microcavity were then performed for different aluminum
concentrations of the Alq3 solution. The microcavity device showed a
good sensibility for the Alq3 molecules and an important shift of the
microcavity photonic resonance was observed. This device might be considered
for a potential aluminiun sensing application.