Characterization and analysis of a microcavity made of porous silicon and porous anodic aluminum oxide

C. ANTONIO HERNANDEZ; E. OSORIO; MAURICIO PACIO CASTILLO; KOROPECKI, R.R.; RAÚL URTEAGA; H. JUAREZ SANTIESTEBAN

Cancum

Congreso; XXVII International materials research congress; 2018

We analyze the optical behavior of a hybrid structure composed of porous silicon and porous anodicalumina for a possible application as a chemical sensor or biosensor. The structure is a microcavitymade by a porous alumina (Al2O3) membrane placed between two Distributed Bragg Reflectors (DBR)of Porous Silicon (PS) centered in 800 nm. The PS was prepared by the galvanostatic anodizingmethod and Al2O3 was fabricated by the two-step anodization method. The SEM images show thephysical structure of the microcavity with a thickness of 16µm. The transmittance spectrum shows theshift towards higher wavelengths when the structure is contaminated with different concentrations ofalcohol, obtaining the parts per million detected by the microcavity. This study is compared with thesimulations corresponding to the structure using the transfer-matrix method and effective mediumtheory (Landau-Lifshitz/Looyenga). The analysis was developed in a grain of the sample which has anarea around millimeters; this in order to reduce roughness in the surface of the alumina and decreasethe light losses by dispersion as a result a higher quality factor is obtained