Fabrication and analysis of 3D colloidal photonic crystals

Photonic band-gap materials have drawn attention from many research groups due to its future application to faster information processing. Different fabrication processes have been developed to manufacture such materials with ease and efficiency. In our experiment, we deployed the methods which are basically of self-organization of polymer micro-particles. At the early stage of the research, self-assembly method was used to fabricate samples of photonic crystals by using the meniscus force. Parameters including temperatures of the platform and concentration of polystyrene spheres are varied. Later, we applied the dipping method to allow the substrate to move with respect to the solution surface. Furthermore, a tilted dipping method was used to grow samples of the best result up to this stage. Apart from the discussion of different growing methods, comparisons among the samples were investigated in details. Transmission dips and reflections peaks of materials fabricated were studied for various fabrication techniques. We would also compare the general qualities of the samples. Shifts of the transmission dips and reflection peaks according the angle of incident light were discussed as well. Further attempts to incorporate silver particles into the structure in order to achieve a 3D photonic band structure are done. Evaluation of success of inclusion is done based on spectra analysis. Larger-size polystyrene spheres are used to enhance the probability of inclusion of silver particles and results are also discussed