Chemical growth process that favours deposition of semiconductor materials from a liquid phase was used to obtain CdS and HgxCd1-xS(0≤x≤0.25)photosensitive thin film electrodes on the stainless steel substrates.The ...Chemical growth process that favours deposition of semiconductor materials from a liquid phase was used to obtain CdS and HgxCd1-xS(0≤x≤0.25)photosensitive thin film electrodes on the stainless steel substrates.The deposition of these series of thin films was carried out under the optimized conditions of temperature(60℃),time(90 min)and pH(10.8±0.2).These films were then employed as photosensitive electrode in an electrochemical photosensing cell consisting of sulphide/polysulphide redox electrolyte and a graphite counter electrode.The cells were illuminated by an input illumination intensity of 13 mW/cm 2 and the cell characteristic parameters namely photocurrent(Iph),photo voltage(Vph),the quantum conversion efficiency(η%)and fill factor(ff %)have been determined.Both Vph and Iph have been found to be boosted as the electrode composition is altered.The conversion efficiency and fill factor enhanced from 0.52%to 1.30%and 31.8%to 37.8%,respectively for the change of electrode composition from 0 to 0.08.Determination of junction ideality factor(nd)showed recombination mechanism at the electrode-electrolyte interface.Barrier height measurements gave Pool-Frenkel type conduction mechanism.The flat band potentials(Vfb)were determined for all the cells and found to be enhanced with x up to 0.08 and then decreased for further increase in x.The lighted junction quality factor(nL)is increased from 1.49 to 2.94 as the photoelectrode composition(x)was varied from 0 to 0.08.The barrier heights(B)at the electrode/electrolyte interfaces were also determined.It is found that B is higher for a cell of electrode composition equal to 0.08.The spectral studies on these cells showed the cut off wavelength(λc)shifted from 530 nm to 800 nm.The transient response studies showed presence of surface states at the interface that causes Fermi-level pinning.Overall,performance of the electrochemical photosensing cell is found to be improved after Hg-corboration in CdS and is optimum at x= 0.08.展开更多
文摘Chemical growth process that favours deposition of semiconductor materials from a liquid phase was used to obtain CdS and HgxCd1-xS(0≤x≤0.25)photosensitive thin film electrodes on the stainless steel substrates.The deposition of these series of thin films was carried out under the optimized conditions of temperature(60℃),time(90 min)and pH(10.8±0.2).These films were then employed as photosensitive electrode in an electrochemical photosensing cell consisting of sulphide/polysulphide redox electrolyte and a graphite counter electrode.The cells were illuminated by an input illumination intensity of 13 mW/cm 2 and the cell characteristic parameters namely photocurrent(Iph),photo voltage(Vph),the quantum conversion efficiency(η%)and fill factor(ff %)have been determined.Both Vph and Iph have been found to be boosted as the electrode composition is altered.The conversion efficiency and fill factor enhanced from 0.52%to 1.30%and 31.8%to 37.8%,respectively for the change of electrode composition from 0 to 0.08.Determination of junction ideality factor(nd)showed recombination mechanism at the electrode-electrolyte interface.Barrier height measurements gave Pool-Frenkel type conduction mechanism.The flat band potentials(Vfb)were determined for all the cells and found to be enhanced with x up to 0.08 and then decreased for further increase in x.The lighted junction quality factor(nL)is increased from 1.49 to 2.94 as the photoelectrode composition(x)was varied from 0 to 0.08.The barrier heights(B)at the electrode/electrolyte interfaces were also determined.It is found that B is higher for a cell of electrode composition equal to 0.08.The spectral studies on these cells showed the cut off wavelength(λc)shifted from 530 nm to 800 nm.The transient response studies showed presence of surface states at the interface that causes Fermi-level pinning.Overall,performance of the electrochemical photosensing cell is found to be improved after Hg-corboration in CdS and is optimum at x= 0.08.
