Templating Colloidal Crystal Growth Using Chirped Surface Relief Gratings

• DOI: 10.1021/acs.langmuir.8b00773
• Publication Date: 2018-06-28T15:09:14Z
• Authors: Russell Mahmood; Andrew Mettry; Andrew C. Hillier
• Keywords: Colloidal crystal

We report a method for controlling the lattice geometry of monodisperse colloidal crystals formed by confined convective self-assembly on substrate patterned with chirped surface relief grating. Chirped gratings were fabricated using laser interference lithography and curved mirror reflector to create photoresist patterns pitch values ranging from ∼500 >10 000 nm spread over planar surface. These nanostructures are shown guide formation various geometries not normally found via assembly surfaces. It is that when grating much larger than diameter particles, trenches serve as compartments deposition particles form close-packed, linear chains. Various ordered structures observed dimensions decrease approach particles. The due specific particle–surface particle–particle interactions. Observed crystal lattices include square, hexagonal, rhombic structures. these explained in terms geometrical constraints imposed pattern particle diameter. can be translated into large area samples corresponding single-pitch substrates. initial monolayer also template growth unique, bilayer rectangular lattices, chains pairs or triplets, graphitelike structured lattices. In addition, coated thin silver layer, configurations produce optical reflection features precisely controlled underlying structure it varies widely spaced close-packed geometries.