(525d) Two-Dimensional Self-Assembly of "Ionic" Colloidal Crystals

Two-dimensional crystals have promising electronic and optical applications. In order to design new functional 2D materials, a greater understanding of the phase behavior of soft particles in a 2D plane must be obtained. We investigate binary systems of particles in two dimensions using molecular dynamics simulations. We simulate "ionic" colloidal interactions, where unlike particles interact via attractive isotropic potentials and like particles interact via repulsive isotropic potentials. The resulting particle systems form crystalline assemblies across a range of compositions and particle sizes, producing compositionally ordered structures with various symmetries and complexities. We report the self-assembly phase diagram of these particles in 2D monolayers and discuss the observed ordered structures, as well as how their structural identification can be streamlined or automated. This work will inform the controlled assembly of 2D colloidal crystals and direct future assembly studies toward favorable areas of phase space.