Fabricación y caracterización óptica de cristales coloidales de alta calidad formados por esferas de SiO2 de 225 nm de diámetro con empaquetamiento fcc crecidos por el método convectivo de auto-ensamblado de deposición vertical.

Octavio Alejandro Castañeda-Uribe,Juan Carlos Salcedo-Reyes,Henry Alberto Méndez-Pinzón,Aura Marina Pedroza-Rodríguez

doi:10.11144/javeriana.sc15-2.faoc

Octavio Alejandro Castañeda-Uribe, Juan Carlos Salcedo-Reyes + Show 2 more

Open Access

https://doi.org/10.11144/javeriana.sc15-2.faoc

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Journal: Universitas Scientiarum	Publication Date: Jun 10, 2010
Citations: 9	License type: cc-by

Abstract

Objective: Fabrication and optical characterization of close-packed 225 nm SiO2 -based colloidal crystals. Materials and methods: The vertical convective self-assembly method is used to grow high-quality 225 nm close-packed SiO2-based colloidal crystals. An annealing process (550°C) is made in order to improve the mechanical stability of the sample. Optical characterization is done by angle-resolved transmission spectroscopy (A-RTS) and structural characterization by Scanning Electron Microscopy (SEM). Results: Both, A-RTS and SEM, show that with the vertical convective self-assembly method, with the appropriate parameters of temperature of evaporation (60°C), volume fraction of the colloidal suspension (0.2% w/w) and acidity (pH=6), highly ordered close packed face centered cubic (fcc) SiO2 based colloidal crystals are obtained. Conclusions: The growth of high-quality (long range order and defect-free) face centered cubic opal-based photonic crystals is reported. Key words: Photonic crystals, colloidal crystals, artificial opals, vertical convective deposition method, Bragg diffraction

Highlights

Photonic meta-materials, artificially engineered materials in which their optical properties are unattainable with naturally occurring materials, attract a great deal of attention mainly because of their ability to control the way in which the electromagnetic radiation interacts with them and, because they represent one of the most important examples of the so-called emerging technologies in the fields of electronics and optoelectronics (1)
A particular kind of photonic meta-materials are the close-packed 3D colloidal crystals: periodic arrangement (face centered cubic and/or hexagonal close packed stacking lattice) of mono-disperse silica or polystyrene nano-spheres with diameters within the wavelength range of visible light in which many novel optical phenomena, that are strongly dependent of the sphere-packing symmetry, are observed (2)
There are many types of interactions between the spheres, the capillary forces acting between the colloidal spheres are larger compared with them

Summary

Introduction

Photonic meta-materials, artificially engineered materials in which their optical properties are unattainable with naturally occurring materials, attract a great deal of attention mainly because of their ability to control the way in which the electromagnetic radiation interacts with them and, because they represent one of the most important examples of the so-called emerging technologies in the fields of electronics and optoelectronics (1). Scattering of light, follows the Bragg’s law, in the same sense that X-rays are diffracted by a family of planes of the atomic crystals. These novel optical phenomena foster a great number of potential applications in advanced optical devices such as waveguides (3), sensors (4), lenses (5) and low threshold lasers (6,7). The controlled evaporation-induced self-assembly vertical deposition method, in which capillary forces produce large high-ordered opal films due to the directional nature of the substrate/colloidal suspension interface, has shown to be one of the more efficient methods (14, 15)

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