A comprehensive study on structural, microstructural, and optical properties of YZnO nanorods prepared by seed morphology-controlled hydrothermal growth

Yttrium-doped ZnO nanorods (YZO-NRs) were grown by the hydrothermal method onto two different seed layers that had been synthesized by sol–gel and subsequently annealed at 500 and 600 °C. The 500 °C-annealed seed layer showed the grain-aggregated surface texture, whereas the 600 °C-annealed seed layer displayed the well-merged smooth surface morphology. Such a difference in seed morphologies affected the material characteristics of the YZO-NRs. Due to the difference in preferential coalescences for each seed morphology, the defective shorter-and-wider YZO-NRs were grown on the grain-aggregated seed layer, while the less-defective longer-and-narrower YZO-NRs were grown on the c-axis preferential smooth seed layer. Accordingly, compared to the YZO-NRs grown on the 500 °C-annealed seed layer, the stronger excitonic emission and the weaker exciton-phonon interaction were observed in the YZO-NRs grown on the 600 °C-annealed seed layer. Herein, the effects of the seed morphology on the material properties of the hydrothermally-grown YZO-NRs were thoroughly investigated by systematic analyses of structural, microstructural, and optical characterizations.