11 documents found, page 1 of 2
Simulation of offshore wind system with three-level converters: HVDC power tran...
Seixas, Mafalda; Melício, Rui; Mendes, Victor; Collares-Pereira, Manuel; Santos, M. P. dosThis paper is on a simulation for offshore wind systems in deep water under cloud scope. The system is equipped with a permanent magnet synchronous generator and a full-power three-level converter, converting the electric energy at variable frequency in one at constant frequency. The control strategies for the three-level are based on proportional integral controllers. The electric energy is injected through a ...
Preparation and characterization of dye-sensitized TiO2 nanorod solar cells
Lijian Meng; Hong Chen; Can Li; Santos, M. P. dosTiO2 nanorods were prepared by DC reactive magnetron sputtering technique and applied to dye-sensitized solar cells (DSSCs). The length of the TiO2 nanorods was varied from 1 μm to 6 μm. The scanning electron microscopy images show that the nanorods are perpendicular to the substrate. Both the X-ray diffraction patterns and Raman scattering results show that the nanorods have an anatase phase; no other phase ha...
Growth of the [110] oriented TiO2 nanorods on ITO substrates by sputtering tech...
Lijian Meng; Hong Chen; Can Li; Santos, M. P. dosTiO2 films have been deposited on ITO substrates by dc reactive magnetron sputtering technique. It has been found that the sputtering pressure is a very important parameter for the structure of the deposited TiO2 films. When the pressure is lower than 1 Pa, the deposited has a dense structure and shows a preferred orientation along the [101] direction. However, the nanorod structure has been obtained as the spu...
Study of vanadium doped ZnO films prepared by dc reactive magnetron sputtering ...
Meng Lijian; Teixeira, Vasco M. P.; Santos, M. P. dosZnO films doped with vanadium (ZnO:V) have been prepared by dc reactive magnetron sputtering technique at different substrate temperatures (RT–500 C). The effects of the substrate temperature on ZnO:V films properties have been studied. XRD measurements show that only ZnO polycrystalline structure has been obtained, no V2O5 or VO2 crystal phase can be observed. It has been found that the film prepared at low su...
Structural modification of TiO2 nanorod films with an influence on the photovol...
Meng Lijian; Li, Can; Santos, M. P. dosTiO2 nanorod films have been deposited on ITO substrates by dc reactive magnetron sputtering technique. The structures of these nanorod films were modified by the variation of the oxygen pressure during the sputtering process. Although all these TiO2 nanorod films deposited at different oxygen pressures show an anatase structure, the orientation of the nanorod films varies with the oxygen pressure. Only a very ...
Effect of annealing temperature on TiO2 nanorod films prepared by dc reactive m...
Meng Lijian; Santos, M. P. dos; Li CanThe anatase TiO2 nanorod films have been prepared on ITO coated glass substrates at room temperature by dc reactive magnetron sputtering technique. The nanorods are highly ordered and are perpendicular to the substrate. XRD measurements show that the anatase nanorods have a preferred orientation along the [110] direction. The prepared nanorods were annealed at different temperatures (200 ºC – 500 ºC) in air for...
Effect of the deposition rate on ITO thin films properties prepared by ion beam...
Meng Lijian; Teixeira, Vasco M. P.; Santos, M. P. dosIndium tin oxide (ITO) thin films have been deposited onto glass substrates at room temperature by ion beam assisted deposition technique at different deposition rates (0.1 -- 0.3 nm/s). The effects of the deposition rate on the structural, optical and electrical properties of the deposited films have been studied. The optical constants of the deposited films were calculated by fitting the transmittance spectra...
Study of indium tin oxide thin films deposited on acrylics substrates by Ion be...
Meng Lijian; Liang Erjun; Gao Jinsong; Teixeira, Vasco M. P.; Santos, M. P. dosIndium tin oxide (ITO) thin films have been deposited onto acrylics (PMMA) substrates by ion beam assisted deposition technique at different oxygen flows. The structural, optical and electrical properties of the deposited films have been characterized by X-ray diffraction, transmittance, FTIR, ellipometry and Hall effect measurements. The optical constants of the deposited films have been calculated by fitting ...
The effect of the ion beam energy on the properties of indium tin oxide thin fi...
Meng Lijian; Gao Jinsong; Santos, M. P. dos; Wang Xiaoyi; Wang TongtongIndium tin oxide (ITO) thin films have been deposited onto polycarbonate substrates by ion beam assisted deposition technique at room temperature. The structural, optical and electrical properties of the films have been characterized by X-ray diffraction, atomic force microscopy, optical transmittance, ellipsometric and Hall effect measurements. The effect of the ion beam energy on the properties of the films h...
Indium tin oxide thin films prepared by ion beam assisted deposition technique ...
Meng Lijian; Gao Jinsong; Teixeira, Vasco M. P.; Santos, M. P. dosIndium tin oxide (ITO) films have been deposited onto glass substrates at room temperature by ion beam assisted deposition technique (IBAD) at different ion beam currents (80 mA – 120 mA). The effect of the ion beam current on films properties has been studied. The films prepared at low ion beam current (80 mA) show an almost amorphous structure. As the ion beam current is increased, films show a preferred orie...