Mesoporous Multilayer Thin Films: Photonic Crystals Sensitive to the Environment

GALO J. DE A. A. SOLER-ILLIA; M.C. FUERTES; P.C. ANGELOMÉ; M.C. MARCHI; H. E. TROIANI; V. LUCA; H. MÍGUEZ

Science Highlights 2007 of LNLS

Año: 2008 p. 13 - 17

1518-0204

Photonic Crystals made up of stacked mesoporous thin films (MTF) were produced by sequential deposition. These materials present order at different length scales: atomic (local stucture), mesoscopic (ordered mesopores) and submicronic (controlled thickness), which could be accurately assessed by Small Angle X-Ray Scattering (2D SAXS, D11A SAXS1) and X-Ray Reflectometry (XRR, D10A XRD2). Each MTF building block of a complex multilayer architecture behaves like an “optical switch” in the presence of vapours. Its electronic density (and therefore the refractive index) changes due to capillary condensation of a given solvent within the pore systems. This leads to the possibility of creating photonic crystals which are responsive to environment, with promising applications in selective sensing or active waveguides.