Three-dimensional photonic bandgap crystals of titania hollow spheres at visi…

Abstract A non-close-packed three-dimensional photonic crystal of titania hollow spheres has been fabricated. The fabricated process is based on the silica template technique, thermal sintering, and the sol–gel process. The bandstructure calculations and optical measurements both indicate that a quasi-full three-dimensional photonic bandgap located at the visible wavelength has been presen…