Growth of Indium Oxide and Zinc-Doped Indium Oxide Nanostructures


  • The authors acknowledge the support of the Nano Science Unit of NSTI, DST, India for making available the TEM and EDX facilities needed for our research work. This research work was supported by financial grant RP 01933 by DST India and SR/S2/CMP-13/2010 by SERS-DST, India.


The growth of zinc-doped indium oxide nanostructures, from mesocontainers to nanowires, by thermal vapor transport of an In2O3 + ZnO mixed precursor at a temperature of 960°C under a flow of argon gas mixed with ethanol vapors (reducing environment) and water vapors (oxidizing environment) is reported. The evolution of mesocontainers is systematically studied as a function of growth time by scanning electron microscopy (SEM) and local energy dispersive X-ray (EDX) spectroscopy. Interestingly, the initial growth is found to be dominated by the formation of ZnO nanocrystallites, followed by the formation of ZnO beaded cable-like structures, and finally nucleation of Zn-doped indium oxide mesocontainer structures at the end of ZnO beaded cable-like structures. These Zn-doped IO mesocontainers appear to have regular crystalline facets with pyramidal holes. The growth and morphological evolution of such structures are discussed in terms of the competitive growth of Zn/In oxides through a bottom-up vapor-solid (VS) mechanism. Surprisingly, a mere change of growth environment from reducing to oxidizing (or inert) results in the growth of In2O3-ZnO nanowires (or nanorods). This study gives an insight into the growth of In2O3-ZnO ternary oxide nanostructures which may have potential application in next generation flexible optoelectronic devices.