Infiltration of ZnO in polymeric photonic crystal by the sol–gel process

Three-dimensionally ordered photonic crystals were fabricated using the vertical self-assembly method from colloidal polystyrene spheres of sub-micrometre diameters. Structural and optical characterization results indicate the extent of good ordering present in these samples. The photonic stop band was tuned by infiltrating two important oxide materials, namely, SiO2 and ZnO. Infiltration was done using a low cost room-temperature sol-gel process which does not require any sophisticated instrumentation. The optical measurements clearly demonstrate that the infiltration is significant. The experimentally measured values of wavelength shift and peak reflectance were compared with theoretically estimated values and found to be in good agreement.