8 V, the ZnO (002) peak intensity was gradually increased and the Ni/PET peaks were decreased check details relatively. This may be caused by the thicker and closely
packed ZnO as shown in Figure 4. To obtain a single ZnO nanorod for TEM images and SAED patterns, the ZnO NRAs integrated sample (Figure 2) was agitated in ethanol solution by ultrasonication. In Figure 5b, the single ZnO nanorod with size/height of 75/600 nm was shown, and the indexed SAED pattern confirmed that the ZnO nanorod was well crystallized with the wurtzite structure. As can be seen in the inset of Figure 5b, the lattice spacing of 0.52 nm was observed in the lattice fringes, which was also in well agreement with the d-spacing Selleck SCH772984 of the ZnO (002) crystal plane corresponding to 2θ = 34.4°. Figure 5 XRD patterns and TEM images. (a) Synthesized ZnO on the seed-coated CT substrate at different external cathodic voltages from −1.6 to −2.8 V for 1 h under ultrasonic agitation, and (b) TEM image (left) and SAED pattern (right)
of the single nanorod detached from the ZnO NRAs grown at −2 V. For comparison, the XRD pattern of bare CT substrate is also given in (a). The inset of (b) shows the HR TEM image of the ZnO nanorod. Figure 6 shows the room-temperature PL spectra of the bare CT substrate and the synthesized ZnO on the seed-coated CT substrate at different external cathodic voltages from −1.6 to −2.8 V for 1 h under ultrasonic agitation. The inset shows the PL peak intensity and full width at half ABT263 maximum (FWHM) of the synthesized ZnO as a
function of external cathodic voltage. Here, the PL emission was detected with an excitation at 266 nm using an Nd-YAG laser source. For the bare CT substrate, there was no PL emission peak due to the absence of the ZnO. Similarly, for the rarely synthesized ZnO on the seed-coated CT substrate under a low external cathodic voltage of −1.6 V, a very weak PL emission peak was observed in the ultraviolet (UV) wavelength region. However, for the ZnO-deposited samples with external cathodic voltages of −2, −2.4, and −2.8 V, the narrow PL emission Dimethyl sulfoxide peaks were observed at wavelengths of 374.3, 377.8, and 380.2 nm, respectively. These PL emissions were attributed to the near band edge (NBE) transition and radial recombination in the direct bandgap of the deposited ZnO. Particularly, the PL intensity of UV emission was largely increased at −2 V (i.e., integrated ZnO NRAs on the seed-coated CT substrate). As shown in the inset, the PL intensity of UV emission at −2 V was increased by 10.5 times compared to that at −2.8 V and its FWHM was also minimized to 162 meV. This enhancement was caused mainly by the size and density of ZnO NRAs. As the size of ZnO nanorods is decreased and their surface area is increased, the incident photon-to-electron conversion efficiency and PL property can be improved .