Investigation of indium oxide as a self-catalyst in ZnO/ZnInO heterostructure nanowires growth

Abstract

We investigated the self-catalytic role of indium oxide in the growth process of ZnO/ZnInO heterostructure nanowires on Si(111). The prepared nanowires had hexagonal cross sections and were tapered with tip diameters of 90 ± 5 nm and base diameters of 230 ± 5 nm. Energy dispersive X-ray and field emission Auger spectroscopies indicated that the grown nanowires were heterostructures of ZnO and ZnInO. Analysis of the early growth process revealed that indium may play a self-catalytic role. Therefore, the vapor-liquid-solid mechanism is likely to be responsible for growth of ZnO/ZnInO nanowires. X-ray diffraction and room temperature photoluminescence (PL) data demonstrated that the presence of indium results in a decrease in nanowires' crystallinity. These wires produced a large PL emission peak in the ultraviolet (UV) region and a smaller peak in the green region of the electromagnetic spectrum. The UV peak of the ZnO/ZnInO nanowires is blue-shifted with respect to that of pure ZnO nanowires.