DOI: 10.4028/www.scientific.net/AMR.1024.323
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.
Bulk glasses with the chemical composition Gey Se94−yIn6 (8 ⩽ y ⩽ 30
at%) have been prepared from high purity constituent elements.
Fragments of the bulk glasses are used to deposit thin films by vacuum
thermal evaporation. The optical band gaps (Eg s) of the as-deposited films have been measured. The allowed optical transition is found to be indirect. The relation of Eg to the covalent coordination number, Z, is demonstrated by varying the composition parameter y of the thin films. A maximum in the compositional dependence of Eg is attained at Z = 2.63.
The cohesive energies (CE) of the investigated samples have also been
calculated using the method suggested by the chemical bond approach. It
is found that the composition dependence of the CE also possesses a peak
at Z = 2.63.A plausible explanation based on the
bonding considerations between the constituents has been provided for
the understanding of the Eg-Z and CE-Z dependences for these Ge–Se–In thin films.
PACS 61.43.Dq;78.66.Jg