Visualizing defect dynamics by assembling the colloidal graphene lattice

This paper investigates the formation and healing of defects in colloidal graphene, a two-dimensional material analogous to atomic graphene. Using confocal microscopy, the researchers observed the assembly process of pseudo-trivalent patchy particles, directly visualizing defects like grain boundaries and vacancies. A kinetically favored pentagonal defect motif was identified as a seed for larger defects. The study determined the conformational energy of the crystal and followed its evolution during defect rearrangement and healing, revealing that common defects originate in the early growth stages due to the kinetic preference for pentagons over equilibrium hexagons. The findings contribute to understanding defect formation in 2D materials and pave the way for assembling complex 2D colloidal materials.

Piet J. M. Swinkels, Zhe Gong, Stefano Sacanna, Eva G. Noya, Peter Schall