Quantum dots growing of Sn/ZnO nanowires and optimizing the optical properties

In this study, the Zinc Oxide (ZnO) nanowires, doped with crystalline tin (Sn), were grown via simple thermal evaporation of ZnO/SnO۲ quantum dots without using any metal catalysts. We investigated the self-catalytic role of tin dioxide in the growth process of Sn/ZnO nanowires on Si (۰۰۱). The cross-section of the prepared nanowires has been hexagon and was tapered with a diameter between ۴۰ and ۶۰nm and several micrometers in length. Characterizations show that the Sn plays a self-catalyst role when the growth process of Sn/ZnO nanowires grows on catalyst-free substrate. Thus, the growth of Sn/ZnO nanowires probably requires the vapor-liquid-solid mechanism. The X-ray diffraction showed the wurtzite structure for prepared samples with a strong preferred peak (۰۰۲) and also revealed that the increase in the tin concentration causes the decrease in the nanowires' crystallinity. The EDX spectra showed a high percentage of Sn at the tip of the samples. The UV peak of the Sn/ZnO nanowires amounts ۱۴ nm blue-shifted with respect to pure ZnO nanowires confirmed by the UV-Visible absorption. With the increase of the doping percentage, the intensity of the visible emission increased and this amount reached highest peak intensity and maximum quantum yield (QY = ۴۱%) at ۶% of the dopant as the quenching point.

کلیدواژه ها:

Optical properties ، Quantum yield ، VS method ، Quantum dot ، self-catalyst ، Quenching point