Filling-factor tunable titanium dioxide replicas of colloidal crystals were fabricated by using a liquid phase deposition (LPD) technique. Ammonium hexafluorotitanate (NH4)(2)TiF6 was used as a precursor, which was converted slowly to titanium dioxide by hydrolysis with boric acid. After the oxide was formed in voids of latex colloidal crystals, the latex was removed by calcination. By applying the LPD process to the replica again, the filling factor of the replica could be increased in a controllable fashion. With 203 nm template spheres, the peak shift in the similar to490 nm stop band depended linearly on the deposition time for the first 20 min, at a rate of 4.4 nm/min. Thus the position of the Bragg reflection peak could be adjusted precisely by controlling the filling factor of the replica structure. (C) 2002 American Institute of Physics. References: 23
展开▼