Nanostructures in various Au ion-implanted ZnO facets modified using energetic O ions

Area of Science:

• Materials Science
• Nanotechnology
• Solid State Physics

Background:

• Noble metal nanoparticles in semiconductors, particularly gold (Au) in zinc oxide (ZnO), are of significant research interest.
• Understanding nanoparticle behavior under ion irradiation is crucial for developing advanced materials.

Purpose of the Study:

• To investigate the dispersion, precipitation, and damage growth of Au nanoparticles in ZnO.
• To study the structural modifications of ZnO and the behavior of Au nanoparticles under high-energy oxygen (O) ion irradiation.

Main Methods:

• 1 MeV Au+-ion implantation into a-plane and c-plane ZnO, followed by annealing.
• 10 MeV O3+ irradiation to modify Au distribution and ZnO structure.
• Rutherford backscattering spectrometry in channelling mode (RBS-C), Raman spectroscopy, X-ray diffraction (XRD), and Transmission Electron Microscopy (TEM) with Energy Dispersive Spectroscopy (EDS).

Main Results:

• Oxygen irradiation significantly modifies the implanted Au layer and ZnO structure, with facet-dependent effects.
• Irradiation introduces disorder in the O sublattice of a-plane ZnO but not additional strain.
• Local compressive deformation around defects is observed in c-plane ZnO, more pronounced after O irradiation.
• Au-hcp clusters (4-10 nm) were observed, with sizes and shapes largely unaffected by O irradiation.

Conclusions:

• High-energy oxygen ion irradiation is an effective method for modifying the distribution and morphology of gold nanoparticles within zinc oxide.
• The study highlights the anisotropic response of ZnO crystal facets to ion irradiation.
• While ZnO structure is modified, the intrinsic properties of embedded gold nanoparticles remain relatively stable under these irradiation conditions.