Growth Modes of ZnS Nanostructures on the Different Substrates

ZnS nanostructures including nanorods are synthesized on Si substrates with and without a SiO2 overlayer using a vapor transport method with a Au layer as a catalyst. Growth modes of ZnS nanostructures grown on both substrates are characterized with scanning electron microscopy (with elemental analysis), X-ray diffraction, and luminescence measurements. These investigations suggest that different growth mechanisms work for ZnS nanostructures depending on the substrates. A vapor−liquid−solid (VLS) mechanism is favored for ZnS nanostructures on a Si substrate, while a vapor−solid (VS) mechanism is favored for a Si/SiO2 substrate. The origin of the differences is discussed in terms of differences in the interaction of Au with substrates and different catalytic activities as a result.