Growth of Indium Oxide and Zinc‐Doped Indium Oxide Nanostructures

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.