The Effect of Growth Temperature on The Characteristics Of ZnO Nanorods And Its Optical Properties

Abstract

The aim of this research is to identify the effects of growth temperature on the characteristics of ZnO nanorods synthesized by the hydrothermal method. The Zinc oxide (ZnO) nanorods synthesis was carried out through two steps, consisting of the ZnO seed layer deposition and the ZnO nanorods growth. The ZnO seed layer was prepared by a spin coating method using zinc acetate dehydrate and ethanol on ITO substrate. The following ZnO nanorods growth was performed with the modified hydrothermal method by using hexamethylenetetramine (HMT) as a precursor and zinc nitrate with a molar ratio of 1:1 for 6 hours. A variation of ZnO nanorods growth temperatures of HMT 25 mM and 50 mM was performed in this research. The resulted ZnO nanorods were characterized by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) to study their structures and morphology. Transform infrared spectroscopy (FTIR) and ultraviolet-visible spectroscopy (UV-Vis) were utilized to characterize the optical characteristics of ZnO nanorods. In general, the synthesized ZnO nanorods were found to be oriented on the (100) and (101) planes with diameters ranging from 81 nm until 365 nm and rods lengths up to 5.1 m. The HMT 50 mM concentration showed that the higher the growth temperature, the larger the sizes of diameter and length of the ZnO nanorods. The ZnO nanorods synthesized by using the 50 mM HMT concentration at 80 oC presented the most favorable result since it had a small size, diameter, and crystallite size with a large energy gap.

Effects of growth conditions on properties of CBD synthesized ZnO nanorods grown on ultrasonic spray pyrolysis deposited ZnO seed layers

“…The band gap values exhibit a red shift relative to 3.37 eV of bulk ZnO related to the quantum confinement effect of the synthesized nanorods [ 55 ]. A similar trend was observed from other studies [ 66 ]. Contrary to our results, the band gap energy obtained from absorbance spectra increased as the temperature increased from 70 °C to 90 °C due to quantum confinement effect [ 67 ].…”

Effect of GO Solution Temperature on the Structural, Optical and Electrical Properties of ZnO Nanostructured for Photoanode Function

“…The average diameter of the ZnO/GO nanostructures grown at 95˚C GO solution immersion temperature has smallest value compared to other samples. The patterns of this results are similar with previous research and as reported that the increasing temperature of the solution produced adequate heat energy for the atom nucleation which improve the surface mobility to be more active [17]. This demonstrates that the GO solution immersion temperature has a significant influence on the size of ZnO/GO nanostructures.…”

“…As reported by Liang et al, the active materials that has better crystallinity structure would give better dye absorption as well as faster electron injection in DSSC [16]. The full width half maximum (FWHM) value was used to calculate the average crystallite size using the Scherrer equation 1 [17].…”

Growth of variable aspect ratio ZnO nanorods by hydrothermal technique

“…Additionally, Mufti et al found that the morphology and optical properties of ZnO nanorods synthesized from two different precursors using a simplified hydrothermal technique are mainly solution temperature dependent [24]. The aspect ratio (defined as the ratio of nanorods length to diameter) is one of the important variables that can affect the ZnO nanorod's performances.…”