Effects of growth duration on the structural and optical properties of ZnO nanorods grown on seed-layer ZnO/polyethylene terephthalate substrates

• Published in: Applied surface science 2011-10, Vol.257 (24), p.10358-10362
• Main Authors: Jeong, Y.I., Shin, C.M., Heo, J.H., Ryu, H., Lee, W.J., Chang, J.H., Son, C.S., Yun, J.
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; HRTEM; Hydrothermal synthesis; Nanorods; Optical properties; Physics; Polyethylene terephthalates; Polymer substrate; Silicon substrates; Structural properties; Tips; XRD; Zinc oxide; Zinc oxide (ZnO)
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2011.06.078

► ZnO nanorods were well-formed for up to 5 h, but leaned and agglomerated after 5 h of growth. ► The structural and optical properties of ZnO nanorods were improved after 5 and 6 h, respectively. ► The growth properties of ZnO nanorods are dependent on growth duration in hydrothermal method. Well-aligned single crystalline zinc oxide (ZnO) nanorods were successfully grown, by hydrothermal synthesis at a low temperature, on flexible polyethylene terephthalate (PET) substrates with a seed layer. Photoluminescence (PL), field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) measurements were used to analyze the optical and structural properties of ZnO nanorods grown for various durations from 0.5 h to 10 h. Regular and well-aligned ZnO nanorods with diameters ranging from 62 nm to 127 nm and lengths from 0.3 μm to 1.65 μm were formed after almost 5 h of growth. The growth rate of ZnO grown on PET substrates is lower than that grown on Si (1 0 0) substrates. Enlarged TEM images show that the tips of the ZnO nanorods grown for 6 h have a round shape, whereas the tips grown for 10 h are sharpened. The crystal properties of ZnO nanorods can be tuned by using the growth duration as a growth condition. The XRD and PL results indicate that the structural and optical properties of the ZnO nanorods are most improved after 5 h and 6 h of growth, respectively.