Cadmium sulphide (CdS) thin films were deposited on a glass substrate by a relatively simple and ... more Cadmium sulphide (CdS) thin films were deposited on a glass substrate by a relatively simple and cost effective successive ionic layer adsorption and reaction (SILAR) method at temperature 80ºC at different deposition cycles. For a fine nanocrystalline thin film growth, the parameters include concentrations of cationic and ionic precursors, number of immersion cycles, and the immersion time. A study was made to know how dip cycles affects the structural, surface morphological and optical properties of the film using X-ray diffraction (XRD), EDAX, scanning electron microscopy (SEM) and UV-VIS (ultraviolet visible) spectrophotometer. The deposited CdS thin films were found to be greenockite αCdS film with a strong preferred orientation along the (002) plane exhibit hexagonal phase with optical band gaps between 2.38 and 2.70eV. The band gap with a value to a certain extent larger than the distinctive value of the bulk CdS (2.42 eV), can be ascribed to quantum confinement effects due to the nanometer crystallite size of the CdS thin films.
The lead sulphide (PbS) thin films were deposited on a glass substrate using successive ionic lay... more The lead sulphide (PbS) thin films were deposited on a glass substrate using successive ionic layer absorption and reaction (SILAR) method at different number of cycles at a room temperature using lead nitrate, thiourea, and sodium hydroxide as chemical precursors. The optical and structural studies was performed by UV-VIS spectrophotometry, X-ray diffraction (XRD) and SEM. The XRD showed films of cubic (galena), crystalline in nature with the preferential (111) orientation. The PbS thin films obtained under optimal deposition conditions were found to polycrystalline with face centered cubic structure. The lattice parameter, grain size, were calculated. The values of the average crystalline sizes were found to be in the ranges of (7-15) nm. Optical studies was carried out using UV spectrometer and it revealed the existence of direct band gap values in the ranges of (1.58-1.70) eV.
The influence of dip times on the lead sulphide (PbS) thin films deposited on glass slide substr... more The influence of dip times on the lead sulphide (PbS) thin films deposited on glass slide substrates via chemical bath deposition (CBD) technique using chemical precursors, nitrate , and thiourea, ) in alkaline medium at 300K. The optical and structural studies were performed by UV-VIS spectrophotometry and X-ray diffraction (XRD). The XRD showed films of cubic (galena), crystalline in nature with the preferential (111) orientation. The optical studies showed films of direct band gaps in the range of 1.59-1.65 eV.
The influence of dip times on the lead sulphide (PbS) thin films deposited on glass slide substra... more The influence of dip times on the lead sulphide (PbS) thin films deposited on glass slide substrates via chemical bath deposition (CBD) technique using chemical precursors, nitrate, and thiourea in alkaline medium at 300 K was investigated. The optical, structural and morphological studies were performed by UV-vis spectophotometry, X-ray diffraction (XRD) and scanning electron microscopy (SEM) respectively. The XRD showed films of cubic (galena), crystalline in nature with the preferential (111) orientation. The optical studies showed films of direct band gaps in the range of 1.59-1.65 eV
Nanocrystalline Cadmium sulfide (CdS) thin films were prepared by chemical bath deposition techni... more Nanocrystalline Cadmium sulfide (CdS) thin films were prepared by chemical bath deposition technique on a glass substrates at a temperature of 80°C and at different deposition times with composition of cadmium chloride (CdCl2), thiourea (CS (NH2)2), ammonia solution (NH4OH) and triethanolamine (TEA) solution. The characterization of thin films was carried out for the structural, morphological and optical properties using X-ray diffraction (XRD), Scanning electron microscope (SEM) and UV-VIS spectrophotometer. XRD studies show that the preferential orientation (002), analysis shows that the prepared samples have hexagonal crystal structure. Scanning electron microscopy (SEM) reveals small nanosized grains tied up in a fibrous-like porous structure uniformly distributed over the surface of the substrate for the CdS films. A UV-VIS optical spectroscopy study was carried out to determine the band gap of the nanocrystalline CdS thin films. The average band gap was found to be 2.25 eV, which is lower than the bulk value (2.4 eV). The increase in absorption coefficient with photon energy makes the deposited CdS thin film a suitable candidate for the fabrication of solar cells.
Cadmium sulphide (CdS) thin films were deposited on a glass substrate by a relatively simple and ... more Cadmium sulphide (CdS) thin films were deposited on a glass substrate by a relatively simple and cost effective successive ionic layer adsorption and reaction (SILAR) method at temperature 80ºC at different deposition cycles. For a fine nanocrystalline thin film growth, the parameters include concentrations of cationic and ionic precursors, number of immersion cycles, and the immersion time. A study was made to know how dip cycles affects the structural, surface morphological and optical properties of the film using X-ray diffraction (XRD), EDAX, scanning electron microscopy (SEM) and UV-VIS (ultraviolet visible) spectrophotometer. The deposited CdS thin films were found to be greenockite αCdS film with a strong preferred orientation along the (002) plane exhibit hexagonal phase with optical band gaps between 2.38 and 2.70eV. The band gap with a value to a certain extent larger than the distinctive value of the bulk CdS (2.42 eV), can be ascribed to quantum confinement effects due to the nanometer crystallite size of the CdS thin films.
The lead sulphide (PbS) thin films were deposited on a glass substrate using successive ionic lay... more The lead sulphide (PbS) thin films were deposited on a glass substrate using successive ionic layer absorption and reaction (SILAR) method at different number of cycles at a room temperature using lead nitrate, thiourea, and sodium hydroxide as chemical precursors. The optical and structural studies was performed by UV-VIS spectrophotometry, X-ray diffraction (XRD) and SEM. The XRD showed films of cubic (galena), crystalline in nature with the preferential (111) orientation. The PbS thin films obtained under optimal deposition conditions were found to polycrystalline with face centered cubic structure. The lattice parameter, grain size, were calculated. The values of the average crystalline sizes were found to be in the ranges of (7-15) nm. Optical studies was carried out using UV spectrometer and it revealed the existence of direct band gap values in the ranges of (1.58-1.70) eV.
The influence of dip times on the lead sulphide (PbS) thin films deposited on glass slide substr... more The influence of dip times on the lead sulphide (PbS) thin films deposited on glass slide substrates via chemical bath deposition (CBD) technique using chemical precursors, nitrate , and thiourea, ) in alkaline medium at 300K. The optical and structural studies were performed by UV-VIS spectrophotometry and X-ray diffraction (XRD). The XRD showed films of cubic (galena), crystalline in nature with the preferential (111) orientation. The optical studies showed films of direct band gaps in the range of 1.59-1.65 eV.
The influence of dip times on the lead sulphide (PbS) thin films deposited on glass slide substra... more The influence of dip times on the lead sulphide (PbS) thin films deposited on glass slide substrates via chemical bath deposition (CBD) technique using chemical precursors, nitrate, and thiourea in alkaline medium at 300 K was investigated. The optical, structural and morphological studies were performed by UV-vis spectophotometry, X-ray diffraction (XRD) and scanning electron microscopy (SEM) respectively. The XRD showed films of cubic (galena), crystalline in nature with the preferential (111) orientation. The optical studies showed films of direct band gaps in the range of 1.59-1.65 eV
Nanocrystalline Cadmium sulfide (CdS) thin films were prepared by chemical bath deposition techni... more Nanocrystalline Cadmium sulfide (CdS) thin films were prepared by chemical bath deposition technique on a glass substrates at a temperature of 80°C and at different deposition times with composition of cadmium chloride (CdCl2), thiourea (CS (NH2)2), ammonia solution (NH4OH) and triethanolamine (TEA) solution. The characterization of thin films was carried out for the structural, morphological and optical properties using X-ray diffraction (XRD), Scanning electron microscope (SEM) and UV-VIS spectrophotometer. XRD studies show that the preferential orientation (002), analysis shows that the prepared samples have hexagonal crystal structure. Scanning electron microscopy (SEM) reveals small nanosized grains tied up in a fibrous-like porous structure uniformly distributed over the surface of the substrate for the CdS films. A UV-VIS optical spectroscopy study was carried out to determine the band gap of the nanocrystalline CdS thin films. The average band gap was found to be 2.25 eV, which is lower than the bulk value (2.4 eV). The increase in absorption coefficient with photon energy makes the deposited CdS thin film a suitable candidate for the fabrication of solar cells.
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Papers by Kester O Ighodalo
chemical bath deposition (CBD) technique using chemical precursors, nitrate, and thiourea in alkaline medium at 300 K was investigated. The optical, structural and morphological studies were performed by UV-vis spectophotometry, X-ray diffraction (XRD) and scanning electron microscopy (SEM) respectively. The XRD showed films of cubic (galena), crystalline in nature with the
preferential (111) orientation. The optical studies showed films of direct band gaps in the range of 1.59-1.65 eV
on a glass substrates at a temperature of 80°C and at different deposition times with composition of
cadmium chloride (CdCl2), thiourea (CS (NH2)2), ammonia solution (NH4OH) and triethanolamine (TEA)
solution. The characterization of thin films was carried out for the structural, morphological and optical
properties using X-ray diffraction (XRD), Scanning electron microscope (SEM) and UV-VIS
spectrophotometer. XRD studies show that the preferential orientation (002), analysis shows that the
prepared samples have hexagonal crystal structure. Scanning electron microscopy (SEM) reveals small
nanosized grains tied up in a fibrous-like porous structure uniformly distributed over the surface of the
substrate for the CdS films. A UV-VIS optical spectroscopy study was carried out to determine the band
gap of the nanocrystalline CdS thin films. The average band gap was found to be 2.25 eV, which is
lower than the bulk value (2.4 eV). The increase in absorption coefficient with photon energy makes the
deposited CdS thin film a suitable candidate for the fabrication of solar cells.
chemical bath deposition (CBD) technique using chemical precursors, nitrate, and thiourea in alkaline medium at 300 K was investigated. The optical, structural and morphological studies were performed by UV-vis spectophotometry, X-ray diffraction (XRD) and scanning electron microscopy (SEM) respectively. The XRD showed films of cubic (galena), crystalline in nature with the
preferential (111) orientation. The optical studies showed films of direct band gaps in the range of 1.59-1.65 eV
on a glass substrates at a temperature of 80°C and at different deposition times with composition of
cadmium chloride (CdCl2), thiourea (CS (NH2)2), ammonia solution (NH4OH) and triethanolamine (TEA)
solution. The characterization of thin films was carried out for the structural, morphological and optical
properties using X-ray diffraction (XRD), Scanning electron microscope (SEM) and UV-VIS
spectrophotometer. XRD studies show that the preferential orientation (002), analysis shows that the
prepared samples have hexagonal crystal structure. Scanning electron microscopy (SEM) reveals small
nanosized grains tied up in a fibrous-like porous structure uniformly distributed over the surface of the
substrate for the CdS films. A UV-VIS optical spectroscopy study was carried out to determine the band
gap of the nanocrystalline CdS thin films. The average band gap was found to be 2.25 eV, which is
lower than the bulk value (2.4 eV). The increase in absorption coefficient with photon energy makes the
deposited CdS thin film a suitable candidate for the fabrication of solar cells.