Chemical Aspects of Three-Dimensional Photonic Crystals

The chemical aspects of three-dimensional photonic crystals have been reported. Three-dimensional (3D) photonic crystals (PCs) are crystalline materials where the refractive index is periodically modulated on a length scale comparable to the light wavelength. 3D PCs that can reflect light from any direction or guide photons potentially offer revolutionary advances in the next generation microphotonic devices and the integration of existing opto-electronic devices. The control of surface chemistry, composition, and concentration of colloidal particles and choice of dispersion medium are critical to the long-range ordering and orientation in colloidal crystals. Rising interest is witnessed in creating 3D structures from environmentally responsive materials, such as hydrogels, and through infiltration of responsive nanoparticles into the 3D templates.