Percolation lithography: Tuning and freezing disorder in 3D photonic crystals using partial wetting and drying

摘要: Although complex, hierarchical nanoscale geometries with tailored degrees of disorder are commonly found in biological systems, few simple self-assembly routes to fabricating synthetic analogues have been identified. We present two techniques that exploit basic capillary phenomena finely control porous 3D photonic crystals, leading complex and geometries. In the first, we exposed structures mixtures ethanol water partially wet their pores, where small adjustments content controlled degree partial wetting. second, infiltrated thin films volatile alkanes observed a sequence infiltration patterns as liquid evaporated. both cases, macroscopic symmetry breaking was driven by subtle sub-wavelength variations pore geometry directed site-selective liquids. The resulting patterns, well described percolation theory, had significant effects on structures' optical properties, including wavelength-dependence angular dependence scattering. Incorporating cross-linkable resins into our liquids, were able create permanent these properties freezing place filling at arbitrary wetting intermediate stages drying. These illustrate versatility interfacial directing tuning aperiodic structures.