No abstract

To probe the origin of p-type conductivity in Sb-doped ZnO, a careful and detailed synchrotron radiation study was performed. The extended X-ray absorption fine structure and X-ray photoelectron spectroscopy investigations provided the evidence for the formation of the complex defects comprising substitution Sb ions at Zn sites (SbZn) and Zn vacancies within the Sb-doped ZnO lattice. Such complex defects result in the increases of Sb-O coordination number and the Sb valence and thereby lead to the p-type conductivity of Sb-doped ZnO. The back-gate field-effect-transistors based on single nanorod of Sb-doped ZnO were constructed, and the stable p-type conduction behavior was confirmed.

A hybrid flow injection-nanobiosensor system for the detection of glucose at low potential is presented in this paper. For the fabrication of the biosensor, highly ordered gold nanowire arrays (AuNWAs) are synthesized by direct electrodeposition in combination with template approach. Glucose oxidase and horseradish peroxidase are immobilized on the surface of the resultant AuNWAs by cross-linking with glutaraldehyde (GLA) and bovine serum albumin (BSA). In combination with a flow injection system, the biosensor demonstrate high performance in glucose detection with a sensitivity of 25.34 μA • cm −2 • mM −1 , a linear range between 5 and 1000 μM, a detection limit of 1 μM, and a sample throughput of 45 h −1 . High selectivity against uric acid, nitrate and chloride ions is also achieved. In addition, it shows good reproducibility, repeatability and stability, which are beneficial for the practical applications in glucose detection. Finally, the developed nanobiosensor is applied to the detection of glucose in river water and the biosensor presents good performance with a relative standard deviation of 1.33% and a recovery rate of 100.4∼102.9%.

Sb-doped ZnO nanorods were fabricated via electrochemical methods. SbCl3,  Zn(NO3)2 and hexamine mixed solution were used as a precursor. The morphology, composition  and crystallinity of nanorods were characterized using a field emission scanning electron microscope,  energy dispersive X-ray spectroscopy and X-ray diffraction, respectively. The transmitted spectrum  was used to investigate optical properties of Sb-doped ZnO arrays. Single Sb-doped ZnO nanorod field effect transistors were constructed via standard photolithography process.  The dependence of nanorod resistance on the temperature from 5K to 300K and the current  versus voltage curve of the field effect transistor at different temperature from 100K to 300K were measured.  The Sb-doped nanorod showed different electrical properties following the change of temperature. Figure 1

Large scale Sb-doped ZnO nanorod arrays were grown utilizing electrochemical solution method with suitable combination of Zn(NO 3 ) 2 , HMT and SbCl 3 precursors. The influences of the pH value and the substrate on the morphology and the crystallization of Sb-doped ZnO nanorods were investigated in detail. The formed Sb-doped ZnO nanorods were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Characteristics of luminescence and crystal qualities were represented by the room temperature photoluminescence spectroscopy. It was found that the pH value had a great effect on the luminescent intensity of the ultraviolet peak and the defect-related luminescence peak. The Sb-ZnO nanorods with a hexagonal wurtzite structures fabricated under the pH value of 5 showed an intense ultraviolet emission and a weak visible emission, demonstrating the good crystal quality of the nanorods. For the substrates of flexible conductive woven nickel-copper fibers, ITO conductive glass and commercial AZO conductive glass, well-crystallized Sb-doped ZnO nanorods can be all achieved. But the crystallographic orientation of nanorods strongly relied on the substrate type.