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2005, Magasin fra Det Kongelige Bibliotek
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Solar Energy Materials and Solar Cells, 2007
Zinc oxide thin films were potentiostatically electrodeposited from a ZnCl 2 +LiCl bath using two different oxygen precursors: molecular oxygen and hydrogen peroxide. X-ray diffraction (XRD) studies confirmed the presence of the ZnO wurtzite structure with marked preferential orientation along the (0 0 2) axis. The optical transmittance shows a clear absorption edge in the ultraviolet (UV) region which corresponds to an energy band gap of 3.4170.03 eV. As a general rule the higher band gap energies are related to the more transparent films.
This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.
Journal of Electroanalytical Chemistry, 2009
In this study we examined the rhenium photoelectroless deposition process onto p-Si(1 0 0) from HF solutions. In the first stage an energetic characterization through capacitance measurements (Mott-Schottky plots) of the p-Si/HF interface was done. Before the rhenium photoelectroless deposition process, a voltammetric and photovoltammetric analysis of p-Si in ReO À 4 =HF solutions was done. In this study, a decrease of the rhenium deposition charge was observed as a function of the increased HF concentration. This behavior was attributed to competition with the silicon dissolution process when an increased HF concentration was present in the electrolytic bath. A morphologic analysis was completed by means of atomic force microscopy (AFM) for the rhenium deposits obtained by photoelectroless process at different HF concentrations and different deposition times. X-ray photoelectron spectroscopy (XPS) technique was utilized to characterize the rhenium deposits, and it was concluded that the films formed by the photoelectroless process were metallic rhenium with only the uppermost atomic layer containing rhenium oxide species. The hydrogen evolution reaction (HER) on the different p-Si/Re electrode systems synthesized was studied. For the HER on p-Si(1 0 0)/Re electrode systems an overpotential decrease of 0.2 V and a photocurrent increase between one and two orders of magnitude, compared with p-Si(1 0 0) and metallic Re, was found. Additionally, the kinetic parameters of the cathodic reactions in the p-Si and p-Si/Re acidic media were estimated using intensity modulated photocurrent spectroscopy (IMPS). A brief analysis from this technique was done. According to these results, the p-Si/Re electrode system could be a potential photoelectrocatalyst for the HER.
Cadmium selenide (CdSe) nanocrystalline semiconductor thin films have been synthesized by electrodeposition at controlled potential based in the electrochemical reduction process of molecular selenium in dimethyl sulfoxide (DMSO) solution. The nucleation and growth mechanism of this process has been studied. The XRD pattern shows a characteristic polycrystalline hexagonal wurtzite structure with a slight (1 0 1 0) crystallographic preferred orientation. The crystallite size of nanocrystalline CdSe thin films can be simply controlled by the electrodeposition potential. A quantum size effect is deduced from the correlation between the band gap energy and the crystallite size.
In this study, we examined the characterization of Prussian blue deposited onto p-Si(100). A cyclic voltammetry analysis was carried out under illumination showing quasireversibility responses of high and low-spin iron centres in the deposit. Optical measurements were done, where XRD analysis allowed to determine crystallinity while EDS analysis indicated that there is influence in the number of cycles on the film composition. Reflectance measurements confirm the coloration observed in the films. However a Kubelka-Munk analysis demonstrates the presence of blue greenish coloration which is an indication of a mix between Prussian blue and Berlin green films. Finally, this research is oriented to construct electrochemical storage devices which can be in situ loaded by the photovoltaic action of the semiconductor base material-doped silicon. .
In this study, we examined the characterization of Prussian blue deposited onto p-Si(100). A cyclic voltammetry analysis was carried out under illumination showing quasireversibility responses of high and low-spin iron centres in the deposit. Optical measurements were done, where XRD analysis allowed to determine crystallinity while EDS analysis indicated that there is influence in the number of cycles on the film composition. Reflectance measurements confirm the coloration observed in the films. However a Kubelka-Munk analysis demonstrates the presence of blue greenish coloration which is an indication of a mix between Prussian blue and Berlin green films. Finally, this research is oriented to construct electrochemical storage devices which can be in situ loaded by the photovoltaic action of the semiconductor base material-doped silicon. .
Thin Solid Films, 2010
The present work comparatively studies the optical properties of CdO against CdSe samples potentiostatically electrodeposited onto fluorine-doped tin oxide/glasses (FTO). The films were prepared by electrochemical reduction processes in dimethyl sulfoxide (DMSO) solution. The optical properties are studied by transmittance measurements and diffuse reflectance spectra (DRS). Structural properties of the films were also studied by X-ray diffraction spectroscopy (XRD). For CdSe the direct bandgap energy obtained from both transmittance measurements and first derivative peak position of the DRS is 1.69 ± 0.01 eV. In the case of CdO both direct and indirect gaps were found. Careful deconvolution of the spectra allows assigning the direct bandgap energy at 2.52 eV. A first indirect bandgap appears at 2.03 eV, while it is possible to have a second one at 0.46 eV.
Thin Solid Films, 2009
In this study we examined the rhenium electrodeposition process onto p-Si(100) from acidic media. The study was carried out by means of cyclic voltammetry and the potential-steps method from which the corresponding nucleation and growth mechanism were determined. Both methods were performed under illumination using a solar simulator for electron photogeneration. A 3D progressive nucleation, diffusioncontrolled growth of rhenium films was found. Likewise, a morphologic analysis was completed for the deposits obtained at different potential values by means of atomic force microscopy. An energetic characterization through capacitance measurements (Mott-Schottky plots and parallel capacitance) of the p-Si/NO 3 − and p-Si/Re/NO 3 − interfaces was done.
Applied Physics A, 2007
2014
The aim of this research is to build a balanced scorecard model for the Cihan University through identifying requirements as well as the steps necessary for successful implementation in this university that is located in Erbil / Iraq. This requires using a specific model that includes pre-identified steps designed to achieve the research objectives. The problem of this research is to identify the sets of requirements and steps needed to build and implement a viable balanced scorecard as a tool to be used to evaluate strategic performance at Cihan University and how this university can use this proposed model of a Balance Scorecard ( BSC) efficiently and effectively to achieve its strategic objectives. The main conclusion of this research is that; there are different methods that can be used by any organization to build and implement a balanced scorecard, based on the organization's vision, strategies and values.
Vremennik russkogo formalizma, I, 2024
Samuel Fernández; Alfons Fürst (eds.), Clavis Origenis, Aschendorff Verlag, Münster, 2024
The Text, 2024
La tecnología educativa en tiempos de pandemia, 2021
Revista de Psicoterapia, 2020
Journal of Service Science and Management, 2023
Control Engineering Practice, 2016
International Journal of Islamic Education, Research and Multiculturalism (IJIERM), 2021
HAL (Le Centre pour la Communication Scientifique Directe), 2022
Zeszyty Naukowe Uniwersytetu Szczecińskiego Finanse Rynki Finansowe Ubezpieczenia, 2016
Journal of Education, Health and Sport
Probability Surveys, 2014