Photoelectrochemical properties of spray deposited n-ZnIn2Se4 thin films

Zinc indium selenide (ZnIn₂Se₄) thin films have been prepared by spraying a mixture of an equimolar aqueous solution of zinc sulphate (ZnSO₄), indium trichloride (InCl₃), and selenourea (CH₄N₂Se), onto preheated fluorine-doped tin oxide (FTO)-coated glass substrates at optimized conditions of substrate temperature and a solution concentration. The photoelectrochemical (PEC) cell configuration of n-ZnIn₂Se₄/1 M (NaOH+Na₂S+S)/C has been used for studying the current voltage (I–V), spectral response, and capacitance voltage (C–V) characteristics of the films. The PEC study shows that the ZnIn₂Se₄ thin films exhibited n-type conductivity. The junction quality factor in dark (n_d) and light (n_l), series and shunt resistance (R_s and R_sh), fill factor (FF) and efficiency (η) for the cell have been estimated. The measured (FF) and η of the cell are, respectively, found to be 0.435% and 1.47%.     

Properties of spray deposited titanium dioxide thin films and their application in photoelectrocatalysis

Thin films of titanium dioxide were deposited onto optically transparent, electrically conducting substrates (fluorine doped tin oxide on glass). The two oxide layers, SnO₂ and TiO₂, were deposited sequentially by spray pyrolysis. TiO₂ films of up to 800 nm thickness were prepared by varying the quantity of sprayed solution (titanyl acetylacetonate in methanol), at a growth rate of 0.15 nm/s.The effect of film thickness on the structural, optical and photoelectrochemical properties of TiO₂ films was studied. Scanning electron microscopy showed that the polycrystalline anatase films were compact. The grain size increased up to 1100 nm with increase in film thickness, whereas the crystallite size remained constant (40 nm) as shown by X-ray diffraction. The films had a transmittance of more than 70% in the visible region.Junctions of the semiconducting films with aqueous electrolytes were rectifying and photoactive. Films of 330 or 600 nm were thick enough to exhibit maximum photoelectrochemical response for light of a wavelength of 313 or 365 nm, respectively. Under depletion conditions, an IPCE (incident photon to current conversion efficiency) of 0.8 for a 330 nm thick film at 313 nm was obtained.Oxalic acid degradation under UVA light and under sunlight, applying electrical bias, was demonstrated using these electrodes.     

An integrated ISM fuzzy MICMAC approach for modelling the supply chain knowledge flow enablers

The aim of this study is to identify supply chain knowledge flow enablers (SCKFEs) to inspect interrelationships among these enablers and classify these enablers into driving power and dependence power using an integrated interpretive structural modelling (ISM) and fuzzy Matriced Impacts Croisés Multiplication Appliquée á un Classement (MICMAC) methodology. While the ISM methodology analyses the interactions among the SCKFEs, fuzzy MICMAC analysis is employed to obtain insights into the dependencies among the SCKFEs. A total of 34 SCKFEs were identified through the literature review and expert opinion. As an example, an Indian manufacturing organisation is selected that is willing to adopt the successful knowledge flow for improving supply chain (SC) performance to overcome the intense competition among the SC versus SC. The research shows SCKFEs having high driving power and low dependence have strategic importance because of their driving nature, while the SCKFEs having high dependence and low driving power are more performance orientated. Therefore, it is the responsibility of SC executives to address the high driving power SCKFEs for the enhancement of SC performance. This categorisation provides a useful tool to top management to differentiate between independent and dependent SCKFEs and their mutual relationships, helping them focus on those key SCKFEs that are most significant. This gives a clear picture to SC practitioners and decision-makers about number of SCKFEs, interrelationship and dependencies existing among them.     

Physical properties of hematite a-Fe2O3 thin films:application to photoelectrochemical solar cells

The physical properties and photoelectrochemical characterization of aluminium doped hematite α-Fe2CO3, synthesized by spray pyrolysis, have been investigated in regard to solar energy conversion. Stable Al-doped iron (Ⅲ) oxide thin films synthesized by a spray pyrolysis technique reveals an oxygen deficiency, and the oxide exhibits n-type conductivity confirmed by anodic photocurrent generation. The preparative parameters have been optimized to obtain good quality thin films which are uniform and well adherent to the substrate. The deposited iron oxide thin films show the single hematite phase with polycrystalline rhombohedral crystal structure with crystallite size 20-40 nm. Optical analysis enabled to point out the increase in direct band-gap energy from 2.2 to 2.25 eV with doping concentration which is attributed to a blue shift. The dielectric constant and dielectric loss are studied as a function of frequency. To understand the conduction mechanism in the films, AC conductivity is measured. The     

Physical properties of spray deposited CdTe thin films: PEC performance

p-CdTe thin films were prepared by spray pyrolysis under different ambient conditions and characterized using photoelectrochemical(PEC),X-ray diffraction(XRD),scanning electron microscopy,energy-dispersive analysis by X-ray(EDAX),and optical transmission studies.The different preparative parameters viz solution pH, solution quantity,substrate temperature and solution concentration have been optimized by the PEC technique in order to get good-quality photosensitive material.XRD analysis shows the polycrystalline nature of the film,having cubic structure with strong(111) orientation.Micrographs reveal that grains are uniformly distributed over the surface of the substrate indicating the well-defined growth of polycrystalline CdTe thin film.The EDAX study for the sample deposited at optimized preparative parameters shows the nearly stoichiometric Cd:Te ratio.Optical absorption shows the presence of direct transition with band gap energy of 1.5 eV.Deposited films exhibit the highest photocurrent of 2.3 mA,a photovoltage of 462 mV,a 0.48 fill factor and 3.4%efficiency for the optimized preparative parameters.