Synthesis of monodisperse SiO₂ colloidal microspheres and its growth of colloidal crystals

An improvement to the traditional Stöber-Fink route to synthesize SiO₂ colloidal microspheres was achieved, and the highly monodisperse SiO₂ colloidal microspheres were synthesized using the improved seed-growth method. Their size-control precision and shape sphericity are improved for these SiO₂ colloidal microspheres. The SiO₂ colloidal crystal was assembled using vertical deposition technique, and their microstructures and optical properties are characterized with the photonic band-gap (PBG) at near infrared wavelength. The effects of SiO₂ colloidal microspheres size on the photonic band-gap are revealed, for these SiO₂ colloidal crystals from the vertical deposition.