The growth mechanism in a heteroepitaxy of oxide nanodots is investigated by combination of the x-ray photoelectron spectroscopy (XPS), atomic force microscopy and theoretical modeling. In contrast to the majority of semiconductor systems, in the studied metal oxide system of Cu2O – SrTiO3(100) the growth process starts without wetting layer formation with appearance of small ( ~ 10 nm) square-based planar Cu2O nanodots. Continued deposition leads mainly to increase of the nanodot density, practically, without change of their size. Only after reaching some critical density (~ 1013 cm-2 for 760 K growth temperature), growth of scattered, significantly larger islands starts through the coalescence of small nanodots. XPS analysis suggests that the interface between small nanodots and substrate is abrupt with only weak Cu – O(SrTiO3) interaction.
Revised: January 10, 2008 |
Published: November 8, 2004
Citation
Lyubinetsky I., A. El-Azab, A.S. Lea, S. Thevuthasan, and D.R. Baer. 2004.Initial Stages of Oxide Nanodot Heteroepitaxial Growth: Cu2O on SrTiO3(100).Applied Physics Letters 85, no. 19:4481-4483.PNNL-SA-42675.