Fabrication of cylindrical opals and inverse opals and their optical properties

Abstract

Hollow and solid cylindrical opals and inverse opals have been made by the self-assembly method in a capillary. The mechanism as well as the assembly process of monodispersed microspheres self-assembly in a capillary has been investigated. By the vertical self-assembly method, hollow cylindrical polystyrene opals and silica inverse opals of different radii have been made in capillaries; whereas cylindrical solid opals and inverse opals have been prepared under the interactions of gravity sedimentation, evaporation induced micro-flow, liquid surface tension and capillary tension. The growth process of producing solid photonic crystals in capillaries have been described and discussed. By scanning electron microscope, we characterize the internal structure of the samples and with spectrometer we test the reflection spectra of these films. Results show that the substrate curvature radius and microsphere size are the main factors that affect the quality of hollow cylindrical opal and inverse opal films while microsphere size has influence on the internal structure of solid cylindrical opals and inverse opals.