Reflectance of surfactant-templated mesoporous silica thin films: Simulations versus experiments

THIN SOLID FILMS

卷:518

Article

Hutchinson, Neal J.¹  Coquil, Thomas¹  Richman, Erik K.²  Tolbert, Sarah H.²  Pilon, Laurent¹ 

[1] Univ Calif Los Angeles, Henry Samueli Sch Engn & Appl Sci, Dept Mech & Aerosp Engn, Los Angeles, CA 90095 USA

[2] Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA

关键词: Mesoporous;    Nanocomposite;    Optical properties;    Nanophotonics;    Effective medium approximation;    Photocatalysis;   

DOI  :  10.1016/j.tsf.2009.08.006

来源: Elsevier

【 摘 要 】

In this study, cubic and hexagonal mesoporous amorphous silica thin films were synthesized using evaporation-induced self-assembly process followed by calcination leaving highly ordered spherical or cylindrical pores in a silica matrix. The films featured pores with diameter between 4 and 11 nm, lattice parameter from 7.8 to 24 nm, and porosity between 22% and 45%. All films were dehydrated prior to reflectance measurements except for one film which was fully hydrated. The present study compares the spectral reflectance measured experimentally between 400 and 900 runt with that computed numerically by solving three-dimensional Maxwell's equations in mesoporous silica thin films with the same morphology as those synthesized. The matrix was assumed to have the same optical properties as bulk fused silica. The pore optical properties were either those of air or liquid water whether the film was dehydrated or hydrated, respectively. Excellent agreement was found between experimental and numerical reflectance for both cubic and hexagonal mesoporous silica films. This study experimentally validates our simulation too] and offers the prospect of ab-initio design of nanocomposite materials with arbitrary optical properties without using effective medium approximation or mixing rules. (C) 2009 Elsevier BY. All rights reserved.

【 授权许可】

Free