An-Najah Staff

A facile and low-cost strategy to improve stability and conversion efficiency of CdSe film electrodes prepared by chemical bath deposition (CBD) onto FTO/glass substrates, is described. The naked CdSe film electrodes, with band gap value 1.8 eV, photo-corroded under the photoelectrochemical (PEC) working conditions and exhibited no photocurrent. The CdSe film peeled out in short times. Attempts made to enhance stability and efficiency of naked CdSe electrodes, by chemical etching or pre-scratching the FTO surface with fine sand-paper, failed to improve film PEC characteristics. Annealing the glass/FTO/CdSe film also failed to improve its PEC stability or efficiency. When coated with the electro-active species Tetra(-4-pyridyl)porphyrinatomanganese^III/II sulfate embedded inside polysiloxane films (MnPyP/Polysil) the CdSe films did not peel out under the PEC conditions. The coated electrode (glass/FTO/CdSe/MnPyP/Polysil) clearly exhibited photocurrents. Pre-annealing the naked CdSe film at 350 °C, followed by coating with MnPyP/Polysil further enhanced the electrode PEC characteristics. Additional heating of the prepared glass/FTO/CdSe/MnPyP/Polysil electrode at 120 °C also enhanced its PEC characteristics. The mode of action of the MnPyP/Polysil coating has been attributed to its ability to behave as a charge transfer catalyst at the solid/liquid interface. The new technique described here could also be potentially valuable for other types of thin film electrode materials.

A facile and low-cost strategy to improve stability and conversion efficiency of CdSe film electrodes prepared by chemical bath deposition (CBD) onto FTO/glass substrates, is described. The naked CdSe film electrodes, with band gap value 1.8 eV, photo-corroded under the photoelectrochemical (PEC) working conditions and exhibited no photocurrent. The CdSe film peeled out in short times. Attempts made to enhance stability and efficiency of naked CdSe electrodes, by chemical etching or pre-scratching the FTO surface with fine sand-paper, failed to improve film PEC characteristics. Annealing the glass/FTO/CdSe film also failed to improve its PEC stability or efficiency. When coated with the electro-active species Tetra(-4-pyridyl)porphyrinatomanganese^III/II sulfate embedded inside polysiloxane films (MnPyP/Polysil) the CdSe films did not peel out under the PEC conditions. The coated electrode (glass/FTO/CdSe/MnPyP/Polysil) clearly exhibited photocurrents. Pre-annealing the naked CdSe film at 350 °C, followed by coating with MnPyP/Polysil further enhanced the electrode PEC characteristics. Additional heating of the prepared glass/FTO/CdSe/MnPyP/Polysil electrode at 120 °C also enhanced its PEC characteristics. The mode of action of the MnPyP/Polysil coating has been attributed to its ability to behave as a charge transfer catalyst at the solid/liquid interface. The new technique described here could also be potentially valuable for other types of thin film electrode materials.

CdS thin films have been deposited onto FTO/glass substrates by two different techniques, electrochemical deposition (ECD) and chemical bath deposition (CBD). Feasibility of using these two film types in photoelectrochemical processes has been critically investigated here. The films were comparatively characterized by a number of techniques (solid state absorption spectra, solid state photoluminescence spectra, XRD and SEM). PEC characteristics of the electrodes, including current density–voltage (J–V) plots, conversion efficiency (η), stability and fill-factor (FF) were then studied. The results show that both systems involved nano-sized CdS particles living in coagulates. The ECD was thinner and more uniform than the CBD system. The CBD films were more effective in PEC processes than the ECD counterparts. Effect of annealing on characteristics of both electrode systems has been investigated. Annealing enhanced both film characteristics, but the CBD was affected to a higher extent, and the annealed CBD film was more effective than the ECD counterpart.

CdS thin films have been deposited onto FTO/glass substrates by two different techniques, electrochemical deposition (ECD) and chemical bath deposition (CBD). Feasibility of using these two film types in photoelectrochemical processes has been critically investigated here. The films were comparatively characterized by a number of techniques (solid state absorption spectra, solid state photoluminescence spectra, XRD and SEM). PEC characteristics of the electrodes, including current density–voltage (J–V) plots, conversion efficiency (η), stability and fill-factor (FF) were then studied. The results show that both systems involved nano-sized CdS particles living in coagulates. The ECD was thinner and more uniform than the CBD system. The CBD films were more effective in PEC processes than the ECD counterparts. Effect of annealing on characteristics of both electrode systems has been investigated. Annealing enhanced both film characteristics, but the CBD was affected to a higher extent, and the annealed CBD film was more effective than the ECD counterpart.

CdS thin films have been deposited onto FTO/glass substrates by two different techniques, electrochemical deposition (ECD) and chemical bath deposition (CBD). Feasibility of using these two film types in photoelectrochemical processes has been critically investigated here. The films were comparatively characterized by a number of techniques (solid state absorption spectra, solid state photoluminescence spectra, XRD and SEM). PEC characteristics of the electrodes, including current densityevoltage (JeV) plots, conversion efficiency (h), stability and fill-factor (FF) were then studied. The results show that both systems involved nano-sized CdS particles living in coagulates. The ECD was thinner and more uniform than the CBD system. The CBD films were more effective in PEC processes than the ECD counterparts. Effect of annealing on characteristics of both electrode systems has been investigated. Annealing enhanced both film characteristics, but the CBD was affected to a higher extent, and the annealed CBD film was more effective than the ECD counterpart.
2013 Published by Elsevier Masson SAS.