Preparation of opal structurated photonic crystal by using porous SiO2 hollow spheres and its optical applications

Abstract

Materials with low refractive indices have high transmittance and high optical sensitivity In recent years the application of materials with low refractive indices in the optical field has attracted considerable attention In this study we synthesized porous SiO2 hollow spheres with a low refractive index by using a hard template method and controlled their refractive indices by changing precursor concentrations to synthesize shells of different thicknesses Changing the angle of incident light on the prepared colloidal crystal caused a large deviation in the photonic band gap Iridescent color changes could be observed with the naked eye demonstrating high angular resolution which is expected to be a priority for next-generation sensors In addition more analyte was loaded by the porous shells and metal nanoparticles were spaced out to improve the generation of hotspots which produced a high Raman signal intensity in the material’s application as a surface-enhanced Raman scattering substrate

Date of Award	2020
Original language	English
Supervisor	Yu-chun Wu (Supervisor)