Long-term oxidization and phase transition of InN nanotextures

Abstract

The long-term (6 months) oxidization of hcp-InN (wurtzite, InN-w) nanostructures (crystalline/amorphous) synthesized on Si [100] substrates is analyzed. The densely packed layers of InN-w nanostructures (5-40 nm) are shown to be oxidized by atmospheric oxygen via the formation of an intermediate amorphous In-O x-N y (indium oxynitride) phase to a final bi-phase hcp-InN/bcc-In 2O 3 nanotexture. High-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, electron energy loss spectroscopy and selected area electron diffraction are used to identify amorphous In-O x-N y oxynitride phase. When the oxidized area exceeds the critical size of 5 nm, the amorphous In-O x-N y phase eventually undergoes phase transition via a slow chemical reaction of atomic oxygen with the indium atoms, forming a single bcc In 2O 3 phase. © 2011 Sarantopoulou et al.