Layer-by-Layer Growth of Multicomponent Colloidal Crystals Over Large Areas

Self-assembly of different sized colloidal particles into multicomponent crystals results in novel material properties compared to the properties of the individual components alone. The formation of binary and, for the first time, ternary colloidal crystals through a simple and inexpensive confinedarea evaporation-induced layer-by-layer (LBL) assembly method is reported. The proposed method produces high quality multicomponent colloidal crystal films over a broad range of particle size-ratios and large surface areas (cm(2)) from silica/polystyrene colloidal suspensions of low concentration. By adjusting the size-ratio and concentration of the colloidal particles, complex crystals of tunable stoichiometries are fabricated and their structural characteristics are further confirmed with reported crystal analogues. In addition, complex structures form as a result of the interplay of the template layer effect, the surface forces exerted by the meniscus of the drying liquid, the space filling principle, and entropic forces. Thus, this LBL approach is a versatile way to grow colloidal crystals with binary, ternary, or more complex structures.