Porous silicon microcavities: synthesis, characterization, and application to photonic barcode devices
1 Centro de Tecnologías Físicas, Unidad Asociada ICMM/CSIC-UPV, Universidad Politécnica de Valencia, Av. Los Naranjos s/n, Valencia, 46022, Spain
2 Instituto de Ciencia de Materiales de Madrid CSIC, Madrid, 28049, Spain
Nanoscale Research Letters 2012, 7:497 doi:10.1186/1556-276X-7-497Published: 3 September 2012
We have recently developed a new type of porous silicon we name as porous silicon colloids. They consist of almost perfect spherical silicon nanoparticles with a very smooth surface, able to scatter (and also trap) light very efficiently in a large-span frequency range. Porous silicon colloids have unique properties because of the following: (a) they behave as optical microcavities with a high refractive index, and (b) the intrinsic photoluminescence (PL) emission is coupled to the optical modes of the microcavity resulting in a unique luminescence spectrum profile. The PL spectrum constitutes an optical fingerprint identifying each particle, with application for biosensing.
In this paper, we review the synthesis of silicon colloids for developing porous nanoparticles. We also report on the optical properties with special emphasis in the PL emission of porous silicon microcavities. Finally, we present the photonic barcode concept.