Preparation And Properties Of Photonic Colloidal Crystals

Photonic colloidal crystals (PCCs) have attracted increasing attention since their proposalbecause of their potential applications in preparing bionic materials, improving photonics,simulating traditional crystallography, etc. Controlling experimental conditions and studyingexperimental mechanism should be continue researched, when using an easy and low-costmethod to prepare large-scale and high-quality three-dimensional (3D) PCCs. In the other hand,the specific frequency photon is closed in the point of the defect or propagated along the defectswhen specific defects are inserted in PCCs. So using an easy method to insert defects in PCCs,which induces defect states in band gaps also increased great attention until now. In this paper,research was carried out from the two above aspects. The main content and results achieved inthis thesis are summarized as follows:1. Polystyrene (PS) colloidal microspheres and silicon dioxide (SiO2) colloidal microspheres,with monodisperse, narrow size distribution(relative standard deviation is below5%), andcontrollable sizes were prepared using emulsion polymerization method and modified Stobermethod, respectively.-COOH functional groups can replace-OH functional groups conjugated tothe surface of synthesized SiO2colloidal microspheres through silane-coupling reaction.Evaporation-induced assembly method at55oC,20kPa was used to prepare high-quality3DPCCs.2. Prepared PS PCCs (SiO2gul was filled into the void of PS colloidal microspheres) byco-assembly method. SiO2inverse PCCs were introduced after annealed at300oC or500oC.Shrinking percentage of PS colloidal microspheres was enlarged with enhancing the temperatureof annealing, which make the PBG positions of SiO2inverse PCCs had blue shift.3. Defect layers were introduced outside of the3D SiO2PCCs by the combination ofphotolithography and evaporation-induced assembly method. Defect layers induced defect statesin the PBGs. At the same time, defect layers consist of different materials make the PBGpositions had different shifts.4. Demonstrated the preparation of3D PCCs possessing designed defects by a combination ofevaporation-induced assembly method and photolithography. The inserted defect layers induced defect states. The PBG position of a PCC inserted photoresist strips defect layer had a blue shift,and the PBG position of a PCCs inserted air-core strips defect layer had a red shift.