Crystal facet engineering: Christmas tree or Taipei tower-like nanostructures

The work of GEMaC researchers and engineers is on the cover of Physica Status Solidi RRL of June.

In situ gallium doping during the metal-organic chemical vapor deposition (MOCVD) growth of Au-catalyzed zinc oxide nanowires induces the formation of new and unexpected Oxygen-polar surfaces, demonstrating that crystal facet engineering can be achieved through a modification of surface energies. Nanostructures having opposite polarities are generated: Christmas trees grown along +c(0001) axis exhibit overhangs, while Taipei towers grown along –c (000-1) axis show terraces. The achievement of such ZnO nanostructures with developed O-polar surfaces have a strong potential interest for the realization of sensor devices or photo-catalysis applications that would require specific surface reactivity.
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