Porous silicon optical microcavity for chemical sensing application using tris-(8-hydroxyquinoline) aluminum (Alq₃)

¹ Laboratoire de Photovoltaïque, Semiconducteurs et Nanostructures, Centre de Recherche et des Technologies de l'Énergie, BP 95, Hammam-Lif, 2050, Tunisia
² Laboratoire de Valorisation des Ressources Naturelles et des Matériaux de Récuperation, Centre National de Recherche en Science des Matériaux, BP 95, Hammam-Lif, 2050, Tunisia

Corresponding author: afrah.bardaoui@crten.rnrt.tn

Received: 10 April 2010
Accepted: 14 June 2010
Published online: 2 August 2010

Abstract

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.