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

摘要

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 |xm to 1.65 |j.m were formed after almost 5 h of growth. The growth rate of ZnO grown on PET substrates is lower than that grown on Si (100) substrates. Enlarged TEM images show that the tips of the ZnO nanorods grown for 6h 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.