Sixfold self-assembled hierarchical structures synthesized by direct annealing of Zn microtips

Controlled Growth of Parallel Oriented ZnO Nanostructural Arrays on Ga2O3 Nanowires

“…It is known that 29 monoclinic Ga 2 O 3 might explain the highly symmetric morphology of these NBs since ZnO is known to form similar hierarchical structures on materials with cubic structures. [10][11][12][13] However, it is possible that ZnO nucleates directly on Ga 2 O 3 , as has been observed elsewhere at lower temepratures. 29 Additionally, {101} and {101 j } Ga 2 O 3 -surfaces are orthogonal to the [010] growth direction, have nearly 6-fold symmetry, and show lattice mismatch within 6% and 17%, respectively, with (0001) ZnO.…”

“…From a crystallographic standpoint, it can be proposed that the 3-fold symmetry of (111) ZnGa 2 O 4 would be a good candidate for (0001) ZnO where an approximate lattice mismatch comparing ZnGa 2 O 4 {202̅} and ZnO {101̅0} is only 5%. Nucleation of ZnO on cubic ZnGa 2 O 4 rather than directly on monoclinic Ga 2 O 3 might explain the highly symmetric morphology of these NBs since ZnO is known to form similar hierarchical structures on materials with cubic structures. − …”

“…Although there is a large variety of hierarchically branched morphologies, only those where branches self-assemble regularly and symmetrically around the core are most promising for controlled growth of aligned NS. Such heterostructures have been obtained by growth of ZnO, − Ga 2 O 3 , SnO 2 , and GaAs nanorod branches symmetrically around the nanowire (NW) cores composed of materials with cubic (In 2 O 3 , , Fe 2 O 3 , and Si) and/or hexagonal (wurtzite ZnO − ) crystal structures. If these NWs or nanorods are initially prearranged in a given pattern, subsequently deposited branches will also be aligned as determined by their orientation relative to the core.…”