Reassembling of Ni and Pt catalyst in the vapor–liquid–solid growth of GaN nanowires

The growth of GaN nanowires on sapphire substrates coated with Ni or Pt catalyst was investigated to address their behavior in a vapor–liquid–solid mechanism. Our observations revealed that both the two catalysts, which led to the growth of nanowires, behave rather complex, including diffusion and re-agglomeration from the coated films to the surface of the micro crystals that is formed in an early stage of growth by vapor–solid mechanism. GaN nanowires have a diameter and length of ~100 nm and several tens of micrometers, respectively, and tend to align epitaxially on the facets of the micro crystals.

Graphical abstractRe-assembling of metal catalyst in the course of the growth of GaN nanowires.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Ni and Pt as catalysts for the VLS growth of GaN nanowires. ► Interfacial layers are formed at early stage. ► Catalysts are re-assembled on the interfacial layer in advance of VLS growth. ► Re-assembling makes difficult to control the GaN nanowire growth.