Influence of salt solution concentration on structural properties of ZnO nanorods grown by hydrothermal method

In the present work, ZnO nanorods have been grown, by hydrothermal method, on glass substrate coated with sputtered ZnO thin film seed layer. The effect of the zinc precursor salt concentration is varied to investigate its effect on the grown nanorod properties. X rays diffraction (XRD), scanning electron microscopy (SEM) technique have been used to analyze the nanorods crystalline structure and morphology. UV-visible optical transmittance and photoluminescence (PL) were used to characterize the nanorods' optical properties and electronic defects. The XRD analysis reveals the high texturation along the (002) direction indicating the well alignment of the grown nanorods confirmed by the SEM observation. Increasing the salt solution leads to ZnO nanorods with larger diameter and dense ZnO nanorods array. The nanorods optical transmission is characterized by a non-common linear decreasing with wavelength reduction. An explanation model of this behavior is addressed. The PL result analysis suggests that the synthetized ZnO nanorods are formed with Zn-termination polar face.