I am a researcher in condensed matter physics, with specialization in solid-state physics (Thin film fabrication, material characterization, nanotechnology, nano-fabrication and nanocrystals). Supervisors: Prof. A.J.EKPUNOBI and Prof. D. OKOLI Phone: 2348069219488 Address: 6 Asuquo Offum Street, Abak Local Government Area, Akwa Ibom State, Nigeria
PbSe thin films were electrodeposited onto ITO substrate with variation of deposition voltage (1-... more PbSe thin films were electrodeposited onto ITO substrate with variation of deposition voltage (1-5V). The deposited thin films were characterized using the four point probe technique to determine their electrical properties. The sheet resistivity of the thin films was found to vary from 1.50 x104 (Ωm) to 5.23 x 104(Ωm) and conductivity vary from 1.91 x 10-5 (Ωm)-1 to 7.40x10-5(Ωm)-1, which is within the electrical conductivity range for semiconductor. It was observed that as the refractive index of the incident radiation increases the photon energy increases as well. It was noticed that sample N with 168nm thickness recorded the highest value of refractive index which increases from 2.424-2.643 and sample O with 164 nm thickness revealed the highest peak in all the samples deposited. It shows that as the optical conductivity of the incident radiation increases the photon energy increases. It was observed that sample follows the same thread and sample O with 164nm thickness revealed the highest peak in all the samples deposited
The electrochemical approach was effectively used to create films of both undoped SnSe and Zr-dop... more The electrochemical approach was effectively used to create films of both undoped SnSe and Zr-doped SnSe nanocrystals. Using a multipurpose D8-AdvanceX-ray diffractometer, an EDX analysis, and a 756S UV-Visible spectrophotometer, the produced films were subjected to optical, structural, and composition characterization. The optical band gap energy for Zr-doped SnSe thin films ranges from 1.2 eV to 1.8 eV, while that for undoped SnSe thin films is determined to be 1.0 eV. For all samples, it was discovered that the absorbance values rose as the Zr dopant concentration rose. As the Zr-dopant concentration rises, the transmittance edge moves toward the lowest wavelength. The reflectance value rises as the concentration of Zr-dopant does. The nanocrystalline grains in the undoped SnSe were randomly distributed and clumped together in the SEM image.
Copper Selenide (CuSe) thin films were successfully electrodeposited onto a well cleaned glass su... more Copper Selenide (CuSe) thin films were successfully electrodeposited onto a well cleaned glass substrate (ITO) at different deposition voltage, time and pH. The optical, structural and surface morphology properties of the films were studied by optical absorption analysis, x-ray diffraction and scanning electron microscopy (SEM) analysis respectively. The X-ray studied revealed that CuSe thin films show a hexagonal structure with lattice constant of a=5.852Å and possess polycrystalline nature. The grain size (D) increases as the deposition time increase, while the dislocation density decreases with increase in film thickness. The SEM micrographs revealed that the grains are small with varying size and evenly distributed throughout the smooth substrate surface. Optical absorption analysis revealed that CuSe thin films have band gap energy (Eg) values of 1.9eV-2.0eV. The high absorbance in UV region, high transmittance in VIS, NIR region and low reflectance, possesses by the films makes the materials applicable in P-N junction solar cells, solar energy collection and antireflective coating.
Asian Journal of Physical and Chemical Sciences, 2018
PbSe thin films were electrodeposited onto ITO substrate with variation of deposition voltage (1-... more PbSe thin films were electrodeposited onto ITO substrate with variation of deposition voltage (1-5V). The deposited thin films were characterized using the four point probe technique to determine their electrical properties. The sheet resistivity of the thin films was found to vary from 1.50 x104 (Ωm) to 5.23 x 104(Ωm) and conductivity vary from 1.91 x 10-5 (Ωm)-1 to 7.40x10-5(Ωm)-1, which is within the electrical conductivity range for semiconductor. It was observed that as the refractive index of the incident radiation increases the photon energy increases as well. It was noticed that sample N with 168nm thickness recorded the highest value of refractive index which increases from 2.424-2.643 and sample O with 164 nm thickness revealed the highest peak in all the samples deposited. It shows that as the optical conductivity of the incident radiation increases the photon energy increases. It was observed that sample follows the same thread and sample O with 164nm thickness revealed the highest peak in all the samples deposited
Zirconium doped Lead selenide (PbSe) nanocrystal films were synthesized on FTO substrates by elec... more Zirconium doped Lead selenide (PbSe) nanocrystal films were synthesized on FTO substrates by electrodeposition technique, and analyzed by UV-Visible Spectrophotometer, four-point probes technique, scanning electron microscopy (SEM), X-ray diffractometer and Energy dispersive X-ray analysis (EDX). The results show that the synthesized Zr/PbSe films exhibited an increase in optical absorbance as the deposition pH increased, with the highest absorbance value in the UV region. The forbidden energy gap values of the synthesized films were observed to increase with an increase in deposition pH. A direct forbidden energy gap ranging from (1.80-1.90)eV within the pH value of 7.5-9.0 was recorded. A refractive index range of 0.65-1.25 was observed. The XRD patterns show that the synthesized films exhibit large grain size and polycrystalline and cubic crystal structure. The SEM image exhibits a densely packed uniformed smooth surface of distribution of spherical-shaped grains, which covered the entire substrate. The spherical-shaped-like grains coalesce to form bigger particles with triangular-shaped rough surfaces at a higher value of pH. The film thicknesses were found to decrease from 105.55nm to 100.98nm as the pH increased from 7.5 to 9.0.
Journal of the Indian Chemical Society, Oct 1, 2022
The electrochemical approach was effectively used to create films of both undoped SnSe and Zr-dop... more The electrochemical approach was effectively used to create films of both undoped SnSe and Zr-doped SnSe nanocrystals. Using a multipurpose D8-AdvanceX-ray diffractometer, an EDX analysis, and a 756S UV-Visible spectrophotometer, the produced films were subjected to optical, structural, and composition characterization. The optical band gap energy for Zr-doped SnSe thin films ranges from 1.2 eV to 1.8 eV, while that for undoped SnSe thin films is determined to be 1.0 eV. For all samples, it was discovered that the absorbance values rose as the Zr dopant concentration rose. As the Zr-dopant concentration rises, the transmittance edge moves toward the lowest wavelength. The reflectance value rises as the concentration of Zr-dopant does. The nanocrystalline grains in the undoped SnSe were randomly distributed and clumped together in the SEM image.
The electrochemical approach was effectively used to create films of both undoped SnSe and Zr-dop... more The electrochemical approach was effectively used to create films of both undoped SnSe and Zr-doped SnSe nanocrystals. Using a multipurpose D8-AdvanceX-ray diffractometer, an EDX analysis, and a 756S UV-Visible spectrophotometer, the produced films were subjected to optical, structural, and composition characterization. The optical band gap energy for Zr-doped SnSe thin films ranges from 1.2 eV to 1.8 eV, while that for undoped SnSe thin films is determined to be 1.0 eV. For all samples, it was discovered that the absorbance values rose as the Zr dopant concentration rose. As the Zr-dopant concentration rises, the transmittance edge moves toward the lowest wavelength. The reflectance value rises as the concentration of Zr-dopant does. The nanocrystalline grains in the undoped SnSe were randomly distributed and clumped together in the SEM image.
Impact of doping on the physical properties of PbSe chalcogenide material for photovoltaic application, 2023
In this research, zirconium was chosen as a dopant to improve the photovoltaic properties of lead... more In this research, zirconium was chosen as a dopant to improve the photovoltaic properties of lead selenide films. Using electrochemical deposition, we successfully deposited zirconium-doped lead selenide and undoped lead selenide films on FTO substrates. The X-ray diffraction pattern for the synthesized undoped and doped PbSe films shows a significant peak at the diffraction planes (220), (112), (310), (202), and (212) which confirm to the cubic structure with a preference orientation of the crystallites along the (202) plane. The Zr incorporation in the PbSe matrix opens up additional nucleation sites, inhibiting the formation of crystal grains and elevating the lattice strain, which may be the reason for the lower crystallinity in the PbSe/Zr films. With a thickness of 105.55nm, the undoped PbSe films were found to have resistivity and conductivity values of 6.20 x 10-5 (Ω.m) and 1.61 x 10-6 (S/m), respectively. When the Zr-dopant content was increased by 0.1 mol%, it was observed that the resistivity value climbed to 7.79 x 10-5 (Ω.m) and subsequently steadily decreased within the same range. The shrinkage of the PbSe/Zr films' grain size is responsible for the modest rise in resistivity. With a rise in Zr-dopant, the electrical conductivity falls from 1.61 x 10-6 (S/m) to 1.29 x 10-6 (S/m). An increase in the resistivity caused a drop in the conductivity. The bandgap for undoped PbSe is 1.10 eV. The bandgap was raised to 1.40–1.70 eV after adding Zr-dopant at a 0.1-04 mol% concentration.
Impact of doping on the physical properties of PbSe chalcogenide material for photovoltaic application, 2023
In this research, zirconium was chosen as a dopant to improve the photovoltaic properties of lead... more In this research, zirconium was chosen as a dopant to improve the photovoltaic properties of lead selenide films. Using electrochemical deposition, we successfully deposited zirconium-doped lead selenide and undoped lead selenide films on FTO substrates. The X-ray diffraction pattern for the synthesized undoped and doped PbSe films shows a significant peak at the diffraction planes (220), (112), (310), (202), and (212) which confirm to the cubic structure with a preference orientation of the crystallites along the (202) plane. The Zr incorporation in the PbSe matrix opens up additional nucleation sites, inhibiting the formation of crystal grains and elevating the lattice strain, which may be the reason for the lower crystallinity in the PbSe/Zr films. With a thickness of 105.55nm, the undoped PbSe films were found to have resistivity and conductivity values of 6.20 x 10-5 (Ω.m) and 1.61 x 10-6 (S/m), respectively. When the Zr-dopant content was increased by 0.1 mol%, it was observed that the resistivity value climbed to 7.79 x 10-5 (Ω.m) and subsequently steadily decreased within the same range. The shrinkage of the PbSe/Zr films' grain size is responsible for the modest rise in resistivity. With a rise in Zr-dopant, the electrical conductivity falls from 1.61 x 10-6 (S/m) to 1.29 x 10-6 (S/m). An increase in the resistivity caused a drop in the conductivity. The bandgap for undoped PbSe is 1.10 eV. The bandgap was raised to 1.40–1.70 eV after adding Zr-dopant at a 0.1-04 mol% concentration.
PbSe thin films were electrodeposited onto ITO substrate with variation of deposition voltage (1-... more PbSe thin films were electrodeposited onto ITO substrate with variation of deposition voltage (1-5V). The deposited thin films were characterized using the four point probe technique to determine their electrical properties. The sheet resistivity of the thin films was found to vary from 1.50 x104 (Ωm) to 5.23 x 104(Ωm) and conductivity vary from 1.91 x 10-5 (Ωm)-1 to 7.40x10-5(Ωm)-1, which is within the electrical conductivity range for semiconductor. It was observed that as the refractive index of the incident radiation increases the photon energy increases as well. It was noticed that sample N with 168nm thickness recorded the highest value of refractive index which increases from 2.424-2.643 and sample O with 164 nm thickness revealed the highest peak in all the samples deposited. It shows that as the optical conductivity of the incident radiation increases the photon energy increases. It was observed that sample follows the same thread and sample O with 164nm thickness revealed the highest peak in all the samples deposited
The electrochemical approach was effectively used to create films of both undoped SnSe and Zr-dop... more The electrochemical approach was effectively used to create films of both undoped SnSe and Zr-doped SnSe nanocrystals. Using a multipurpose D8-AdvanceX-ray diffractometer, an EDX analysis, and a 756S UV-Visible spectrophotometer, the produced films were subjected to optical, structural, and composition characterization. The optical band gap energy for Zr-doped SnSe thin films ranges from 1.2 eV to 1.8 eV, while that for undoped SnSe thin films is determined to be 1.0 eV. For all samples, it was discovered that the absorbance values rose as the Zr dopant concentration rose. As the Zr-dopant concentration rises, the transmittance edge moves toward the lowest wavelength. The reflectance value rises as the concentration of Zr-dopant does. The nanocrystalline grains in the undoped SnSe were randomly distributed and clumped together in the SEM image.
Copper Selenide (CuSe) thin films were successfully electrodeposited onto a well cleaned glass su... more Copper Selenide (CuSe) thin films were successfully electrodeposited onto a well cleaned glass substrate (ITO) at different deposition voltage, time and pH. The optical, structural and surface morphology properties of the films were studied by optical absorption analysis, x-ray diffraction and scanning electron microscopy (SEM) analysis respectively. The X-ray studied revealed that CuSe thin films show a hexagonal structure with lattice constant of a=5.852Å and possess polycrystalline nature. The grain size (D) increases as the deposition time increase, while the dislocation density decreases with increase in film thickness. The SEM micrographs revealed that the grains are small with varying size and evenly distributed throughout the smooth substrate surface. Optical absorption analysis revealed that CuSe thin films have band gap energy (Eg) values of 1.9eV-2.0eV. The high absorbance in UV region, high transmittance in VIS, NIR region and low reflectance, possesses by the films makes the materials applicable in P-N junction solar cells, solar energy collection and antireflective coating.
Asian Journal of Physical and Chemical Sciences, 2018
PbSe thin films were electrodeposited onto ITO substrate with variation of deposition voltage (1-... more PbSe thin films were electrodeposited onto ITO substrate with variation of deposition voltage (1-5V). The deposited thin films were characterized using the four point probe technique to determine their electrical properties. The sheet resistivity of the thin films was found to vary from 1.50 x104 (Ωm) to 5.23 x 104(Ωm) and conductivity vary from 1.91 x 10-5 (Ωm)-1 to 7.40x10-5(Ωm)-1, which is within the electrical conductivity range for semiconductor. It was observed that as the refractive index of the incident radiation increases the photon energy increases as well. It was noticed that sample N with 168nm thickness recorded the highest value of refractive index which increases from 2.424-2.643 and sample O with 164 nm thickness revealed the highest peak in all the samples deposited. It shows that as the optical conductivity of the incident radiation increases the photon energy increases. It was observed that sample follows the same thread and sample O with 164nm thickness revealed the highest peak in all the samples deposited
Zirconium doped Lead selenide (PbSe) nanocrystal films were synthesized on FTO substrates by elec... more Zirconium doped Lead selenide (PbSe) nanocrystal films were synthesized on FTO substrates by electrodeposition technique, and analyzed by UV-Visible Spectrophotometer, four-point probes technique, scanning electron microscopy (SEM), X-ray diffractometer and Energy dispersive X-ray analysis (EDX). The results show that the synthesized Zr/PbSe films exhibited an increase in optical absorbance as the deposition pH increased, with the highest absorbance value in the UV region. The forbidden energy gap values of the synthesized films were observed to increase with an increase in deposition pH. A direct forbidden energy gap ranging from (1.80-1.90)eV within the pH value of 7.5-9.0 was recorded. A refractive index range of 0.65-1.25 was observed. The XRD patterns show that the synthesized films exhibit large grain size and polycrystalline and cubic crystal structure. The SEM image exhibits a densely packed uniformed smooth surface of distribution of spherical-shaped grains, which covered the entire substrate. The spherical-shaped-like grains coalesce to form bigger particles with triangular-shaped rough surfaces at a higher value of pH. The film thicknesses were found to decrease from 105.55nm to 100.98nm as the pH increased from 7.5 to 9.0.
Journal of the Indian Chemical Society, Oct 1, 2022
The electrochemical approach was effectively used to create films of both undoped SnSe and Zr-dop... more The electrochemical approach was effectively used to create films of both undoped SnSe and Zr-doped SnSe nanocrystals. Using a multipurpose D8-AdvanceX-ray diffractometer, an EDX analysis, and a 756S UV-Visible spectrophotometer, the produced films were subjected to optical, structural, and composition characterization. The optical band gap energy for Zr-doped SnSe thin films ranges from 1.2 eV to 1.8 eV, while that for undoped SnSe thin films is determined to be 1.0 eV. For all samples, it was discovered that the absorbance values rose as the Zr dopant concentration rose. As the Zr-dopant concentration rises, the transmittance edge moves toward the lowest wavelength. The reflectance value rises as the concentration of Zr-dopant does. The nanocrystalline grains in the undoped SnSe were randomly distributed and clumped together in the SEM image.
The electrochemical approach was effectively used to create films of both undoped SnSe and Zr-dop... more The electrochemical approach was effectively used to create films of both undoped SnSe and Zr-doped SnSe nanocrystals. Using a multipurpose D8-AdvanceX-ray diffractometer, an EDX analysis, and a 756S UV-Visible spectrophotometer, the produced films were subjected to optical, structural, and composition characterization. The optical band gap energy for Zr-doped SnSe thin films ranges from 1.2 eV to 1.8 eV, while that for undoped SnSe thin films is determined to be 1.0 eV. For all samples, it was discovered that the absorbance values rose as the Zr dopant concentration rose. As the Zr-dopant concentration rises, the transmittance edge moves toward the lowest wavelength. The reflectance value rises as the concentration of Zr-dopant does. The nanocrystalline grains in the undoped SnSe were randomly distributed and clumped together in the SEM image.
Impact of doping on the physical properties of PbSe chalcogenide material for photovoltaic application, 2023
In this research, zirconium was chosen as a dopant to improve the photovoltaic properties of lead... more In this research, zirconium was chosen as a dopant to improve the photovoltaic properties of lead selenide films. Using electrochemical deposition, we successfully deposited zirconium-doped lead selenide and undoped lead selenide films on FTO substrates. The X-ray diffraction pattern for the synthesized undoped and doped PbSe films shows a significant peak at the diffraction planes (220), (112), (310), (202), and (212) which confirm to the cubic structure with a preference orientation of the crystallites along the (202) plane. The Zr incorporation in the PbSe matrix opens up additional nucleation sites, inhibiting the formation of crystal grains and elevating the lattice strain, which may be the reason for the lower crystallinity in the PbSe/Zr films. With a thickness of 105.55nm, the undoped PbSe films were found to have resistivity and conductivity values of 6.20 x 10-5 (Ω.m) and 1.61 x 10-6 (S/m), respectively. When the Zr-dopant content was increased by 0.1 mol%, it was observed that the resistivity value climbed to 7.79 x 10-5 (Ω.m) and subsequently steadily decreased within the same range. The shrinkage of the PbSe/Zr films' grain size is responsible for the modest rise in resistivity. With a rise in Zr-dopant, the electrical conductivity falls from 1.61 x 10-6 (S/m) to 1.29 x 10-6 (S/m). An increase in the resistivity caused a drop in the conductivity. The bandgap for undoped PbSe is 1.10 eV. The bandgap was raised to 1.40–1.70 eV after adding Zr-dopant at a 0.1-04 mol% concentration.
Impact of doping on the physical properties of PbSe chalcogenide material for photovoltaic application, 2023
In this research, zirconium was chosen as a dopant to improve the photovoltaic properties of lead... more In this research, zirconium was chosen as a dopant to improve the photovoltaic properties of lead selenide films. Using electrochemical deposition, we successfully deposited zirconium-doped lead selenide and undoped lead selenide films on FTO substrates. The X-ray diffraction pattern for the synthesized undoped and doped PbSe films shows a significant peak at the diffraction planes (220), (112), (310), (202), and (212) which confirm to the cubic structure with a preference orientation of the crystallites along the (202) plane. The Zr incorporation in the PbSe matrix opens up additional nucleation sites, inhibiting the formation of crystal grains and elevating the lattice strain, which may be the reason for the lower crystallinity in the PbSe/Zr films. With a thickness of 105.55nm, the undoped PbSe films were found to have resistivity and conductivity values of 6.20 x 10-5 (Ω.m) and 1.61 x 10-6 (S/m), respectively. When the Zr-dopant content was increased by 0.1 mol%, it was observed that the resistivity value climbed to 7.79 x 10-5 (Ω.m) and subsequently steadily decreased within the same range. The shrinkage of the PbSe/Zr films' grain size is responsible for the modest rise in resistivity. With a rise in Zr-dopant, the electrical conductivity falls from 1.61 x 10-6 (S/m) to 1.29 x 10-6 (S/m). An increase in the resistivity caused a drop in the conductivity. The bandgap for undoped PbSe is 1.10 eV. The bandgap was raised to 1.40–1.70 eV after adding Zr-dopant at a 0.1-04 mol% concentration.
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specific model by Dr. Kufre I Udofia
The deposited thin films were characterized using the four point probe technique to determine their
electrical properties. The sheet resistivity of the thin films was found to vary from 1.50 x104 (Ωm) to
5.23 x 104(Ωm) and conductivity vary from 1.91 x 10-5 (Ωm)-1 to 7.40x10-5(Ωm)-1, which is within the
electrical conductivity range for semiconductor. It was observed that as the refractive index of the
incident radiation increases the photon energy increases as well. It was noticed that sample N with
168nm thickness recorded the highest value of refractive index which increases from 2.424-2.643
and sample O with 164 nm thickness revealed the highest peak in all the samples deposited. It
shows that as the optical conductivity of the incident radiation increases the photon energy
increases. It was observed that sample follows the same thread and sample O with 164nm
thickness revealed the highest peak in all the samples deposited
The deposited thin films were characterized using the four point probe technique to determine their
electrical properties. The sheet resistivity of the thin films was found to vary from 1.50 x104 (Ωm) to
5.23 x 104(Ωm) and conductivity vary from 1.91 x 10-5 (Ωm)-1 to 7.40x10-5(Ωm)-1, which is within the
electrical conductivity range for semiconductor. It was observed that as the refractive index of the
incident radiation increases the photon energy increases as well. It was noticed that sample N with
168nm thickness recorded the highest value of refractive index which increases from 2.424-2.643
and sample O with 164 nm thickness revealed the highest peak in all the samples deposited. It
shows that as the optical conductivity of the incident radiation increases the photon energy
increases. It was observed that sample follows the same thread and sample O with 164nm
thickness revealed the highest peak in all the samples deposited