Ion implantation has been revealed as a potential technique to modify the surface of materials. In this work, MoO3 nanobelts were synthesized on MoO3 whisker surfaces by means of ion implantation with 60 keV nitrogen ions at a dose of 1 × 1016 atom/cm2 and characterized by scanning electron microscopy, Raman spectroscopy, and transmission electron microscopy. The result showed that the nanostructures of MoO3 occurred over the whisker surfaces and had belt-like shapes. The size of the synthesized MoO3 nanobelts mostly ranged from 20 to 60 nm in width and 300 to 800 nm in length. The nanobelts were found to have an orthorhombic crystal structure with growth preferential in the [001] direction. The growth process of the nanobelts based on the common vapor-solid mechanism is discussed. 相似文献
Charge-transporting processable layers at a low temperature is a challenge for fabricating novel, highly stable and flexible optoelectronic devices. In fact, the crystallization of metal oxide usually needs to be processed under a high-temperature to obtain excellent semiconducting properties. In this work, Sn-doped ZnO (TZO) thin films, as electron transporting layers (ETLs) in perovskite solar cells, were prepared via sol–gel method at a temperature of less than 180 °C. The effects of annealing temperature on the properties of TZO thin films were investigated. It was found that the electrical properties of the TZO films were improved with increasing annealing temperature. In addition, an elemental composition analysis revealed that a temperature of only 140 °C sufficed for converting the precursor gel film into TZO film. The perovskite solar cell, which utilized a low-temperature TZO thin film, yielded a better power conversion efficiency than one with high-temperature ETLs (180 °C). These results imply that discovering low-temperature ETL processing for sol–gel enables good-quality metal oxide ETL, which can also be used in flexible solar cell applications.
This paper presents a robustness analysis and design approach for impedance control of a flexible structure mounted manipulator (FSMM) performing contact tasks. In the analysis, the dynamics of the flexible structure are treated as uncertain. The environment is also treated as uncertain, but with force-displacement characteristics satisfying a sector-bound condition. First, a one dimensional model for an end-effector under impedance control is considered. The effect of base flexibility on stability under contact conditions is then assessed via the Popov criterion. Based on these results, an approach to robust impedance control is proposed. It is shown that by augmenting low-order filters within a standard impedance control law, robust global stability in the presence of base flexibility can be achieved. The controller is shown to perform successfully in experiments on a two-link lab-scale FSMM. 相似文献
Functionalization of aniline molecules on zinc oxide(ZnO)nanoparticles is reported using a simple impregnation technique.Functionalized ZnO samples were systematically characterized based on mor-phology,surface and optical properties,and photocatalytic performance towards methyl orange(MO).Aniline functionalization increased the surface charge of the modified ZnO.Compared to pristine ZnO,the aniline-functionalized ZnO yielded faster photodegradation of MO,degrading 98.29% of MO in 60 min and superoxide radicals were the major species during the MO photodegradation reaction.These results indi-cate that the improvement of photocatalytic degradation could be attributed to opposite charge-induced surface adsorption.Hence,protonated amine as a positively charged molecule was expected to increase the surface adsorption of MO(as an anionic dye)on ZnO nanoparticles surfaces,thereby increasing their photocatalvtic degradation performance. 相似文献
Mg(x)Zn1-xO nanoneedles were synthesized on alumina substrate by using thermal oxidation technique under normal atmosphere. Zn powder and MgO powder were mixed and heated to form Mg(x)Zn1-xO with x content of 0-0.3 by mol at heating temperature and time of 400-1000 degrees C and 24 h. The morphology of Mg(x)Zn1-xO nanoneedle was characterized by filed emission scanning electron microscope (FE-SEM). It was found that the needle-like nanostructures with the sharp ends were observed outward from microparticles at 400-800 degrees C. From EDS, XRD, and TEM analysis, it was suggested that Mg(x)Zn1-xO alloy was formed with no segregation of MgO in Mg(x)Zn1-xO alloy after thermal oxidation process. Also, from reflectance spectra, the Mg(x)Zn1-xO nanoneedle exhibited higher energy gap than that of ZnO films for entire Mg content indicating widening band gap energy due to alloying effect. Moreover, we have proposed the growth mechanism of Mg(x)Zn1-xO nanoneedles based on growth kinetic of nucleation formation. This growth model can be explored to explain nanostructure of other metal-oxide alloy prepared by thermal oxidation. 相似文献