Engineering disorder in three-dimensional photonic crystals

We demonstrate the effect of introducing controlled disorder in self-assembled three-dimensional photonic crystals. Disorders are induced through controlling the self-assembling process using an electrolyte of specific concentrations. Structural characterization reveals increase in disorder with increase in concentrations of the electrolyte. Reflectivity and transmittance spectra are measured to probe the photonic stop gap at different levels of controlled disorder. With increase in disorder the stop gap is vanished and that results in a fully random photonic nanostructure where the diffuse scattered intensity reaches up to 100%. The estimated scattering mean free path shows significant reduction for photonic crystals with 100% controlled disorder as compared to those with 0% controlled disorder. Our random photonic nanostructure is unique in which all scatters have the same size and shape. Therefore, we observe the resonant characteristics in the multiple scattering of light.

► We demonstrate the effect of controlled disorder on the optical properties of photonic crystals. ► The disorders are introduced through controlling the self-assembly process using electrolyte of appropriate concentrations. ► With increase in controlled disorder, the photonic stop gap has vanished and that results in a completely disordered photonic structure. ► Our photonic crystals with 100% induced disorder are unique and can exhibit resonant nature in the light scattering, unlike the conventional one.