Ordered Particle Arrays via a Langmuir Transfer Process: Large Area Access to Any Two-Dimensional Bravais Lattice

The preparation of particle arrays on solid substrates is an essential step for the fabrication of functional surfaces and thin-film devices with applications in lithography, optics, photonics, high-density data storage and as adhesive/non-adhesive surfaces. Colloidal self-assembly represents an attractive and scalable route towards hexagonally close-packed particle arrays. To significantly broaden the structural variability, the fabrication of non-close-packed and also non-hexagonal particle arrays are required. Here, we demonstrate how to fabricate non-close-packed particle arrays with symmetries of all possible Bravais lattices in a simple solution-based process. Our process starts with readily self-assembled, hexagonally close-packed monolayers, which are immobilized on an air/water interface. Upon transfer onto the target substrate, stretching along a specific crystallographic direction occurs. This yields non-close-packed structures with non-hexagonal symmetry. We demonstrate how to control the stretching factor by interfacial modification of the target substrate to access all possible Bravais lattices.