Atomic-scale tuning of self-assembled ZnO microscopic patterns: from dendritic fractals to compact island.

How nature uses water molecules to create fascinating patterns ranging from snowflakes to ice cubes has intrigued mankind for centuries. Here we use ZnO to mimic nature's versatility in creating microscopic patterns with tunable morphology. During growth of ZnO on Zn-dominant spheres via chemical vapor deposition, highly regular and symmetric dendritic snowflake patterns and smooth compact islands can be obtained at different growth conditions. We reproduce the dendritic patterns using atomistic Monte Carlo simulations. These findings not only improve understanding of how water molecules form various patterns, but may also be instrumental in tailoring ZnO nanostructures for desirable functionality.