Self-assembling three-dimensional colloidal photonic crystal structure with high crystalline quality

High-quality colloidal crystal multilayers were fabricated from aqueous sol utions by the vertical deposition method. The effect of the evaporation tem perature on the crystalline quality of colloidal crystals was carried out. It is found that with the increase of the evaporation temperature, the coll oidal crystal shows an increasing tendency towards equilibrium face-centere d-cubic phase, and the resulted sample also shows few dislocations and vaca ncies when the balance in the processes of nucleus formation, particle tran sport, and crystallization can be kept. However, with the further increase of the evaporation temperature (above 55 degreesC), a vast amount of defect s appear in the crystal because the fast water evaporation rate, which resu lts in a fast crystal growth rate, will spoil the balance. Optical measurem ents correspond well to the microstructure results. (C) 2001 American Insti tute of Physics.