  One versatile route to the creation of two-dimensional crystal structures on
the nanometer to micrometer scale is the self-assembly of colloidal particles
at an interface. Here, we explore the crystal phases that can be expected from
the self-assembly of mixtures of spherical particles of two different sizes,
which we map to (additive or non-additive) hard-disk mixtures. We map out the
infinite-pressure phase diagram for these mixtures, using Floppy Box Monte
Carlo simulations to systematically sample candidate crystal structures with up
to 12 disks in the unit cell. As a function of the size ratio and number ratio
of the two species of particles, we find a rich variety of periodic crystal
structures. Additionally, we identify random tiling regions to predict random
tiling quasicrystal stability ranges. Increasing non-additivity both gives rise
to additional crystal phases and broadens the stability regime for crystal
structures involving a large number of large-small contacts, including random
tilings. Our results provide useful guidelines for controlling the
self-assembly of colloidal particles at interfaces.
