Self-assembly of chromatic patchy particles with tetrahedrally arranged patches

The achievement of selectivity in the formation of cubic diamond is challenging due to the emergence of competing phases such as its hexagonal polymorph or clathrates possessing similar free energy. Although both polymorphs exhibit a complete photonic bandgap, cubic diamond exhibits it at lower frequencies than the hexagonal counterpart, positioning it as a promising candidate for photonic applications. Herein, we demonstrate that the 1 : 1 mixture of identical patchy particles cannot selectively form the cubic diamond polymorph due to the frustrations present in the system that are manifested in the primary adsorption layer and propagate as the film grows. We provide a plausible explanation for why the binary system under confinement, resembling interactions between the complementary DNA bases, cannot yield the selectivity in the formation of cubic diamond crystals, which is based on the similarities to the antiferromagnetic systems. We always observe a mixture of both hexagonal and cubic diamonds; however, the formation of such stacking hybrids is observed for a wider range of patch sizes compared to the one-component system.