Fabrication, Characterization of SiO2 Nanospheres and SiO2 Opal Photonic Crystals

Abstract

In this report, we presented the usage of Stober method to fabricate SiO2 nanospheres and self-assembly method to make SiO2 opal photonic crystals based on the fabricated SiO2 nanospheres. An averaged size of SiO2 nanospheres was controlled by varying concentrations of NH4OH and TEOS. Crystal structure and morphology of particles was investigated by using X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. Experimental results showed that SiO2 nanospheres possess amorphous crystal structure with sizes ranged from 150 to 300 nm. The diffuse reflection spectra show the reflection peaks of the SiO2 opal photonic crystals from 410 nm to 520 nm.