Nanotechnology 2011, 22:485203.CrossRef Competing interests The authors declare that they have no competing interests. Authors’ contributions AP fabricated and analyzed both the TaOx and HfOx memories and developed the auto measurement program. WB fabricated the AlOx-based memory. DJ fabricated the GdOx-based memory. This research work was carried
out under the instruction of SM. CSL offered the fabrication process. All of the authors revised the manuscript. All authors read and approved the final manuscript.”
“Background ZnO nanostructures have attracted extensive attention over the past few years because of their unique properties for applications in electronic and optoelectronic devices [1–5]. For example, by virtue of the nanosized junction and excellent waveguiding property of nanorods, the ZnO nanorod-based heterojunction Proteases inhibitor CBL-0137 ic50 light-emitting diodes (LEDs) exhibit significantly improved electroluminescence
performance [6–8]. It is well known that the properties and applications of ZnO are crucially dependent on www.selleckchem.com/products/GSK690693.html the microstructures of the materials, such as morphology, size, and orientation. Hence, controllable synthesis of ZnO nanostructures is of great importance to tailor their physical properties and improve device performance [9–11]. So far, ZnO nanostructures have been synthesized by various physical and chemical methods, such as vapor–liquid-solid, molecular beam epitaxy, and solution processes. Among them, room temperature solution route (hydrothermal method, for example) is particularly attractive because it is a simple, low-temperature, and catalyst-free process with no limitation of substrates [1, 12–15]. In addition, by varying the reaction parameters during hydrothermal process, morphology of ZnO nanostructures can be tuned effectively [16]. In this paper, controllable synthesis D-malate dehydrogenase of various ZnO nanostructures on the Si substrate was achieved by tuning hydrothermal growth parameters, such
as the seed layer, solution concentration, reaction temperature, and surfactant. X-ray diffraction (XRD) and photoluminescence (PL) measurements reveal that crystal quality and optical properties crucially depend on the morphology of the ZnO nanostructures. Methods Deposition of ZnO seed layers on the Si substrates Here, ZnO seed layers were prepared by two methods: radio-frequency (RF) magnetron sputtering and dip coating, as described in the following. RF magnetron sputtering The ZnO seed layer was deposited on Si substrates by a conventional RF magnetron sputtering system equipped with a ZnO (99.99%) ceramic target. The sputtering chamber was evacuated to a base pressure of 1.0 × 10−5 Pa and then filled with working gas (pure Ar) to a pressure of 1.0 Pa. After depositing at 600°C with a constant RF power of 80 W for certain time intervals, a layer of ZnO nanoparticles was obtained.