This document summarizes research on cadmium sulfide (CdS) thin films doped with cobalt (Co) prepared using the spray pyrolysis technique. Key findings include:
1. Cd1-xCoxS thin films were deposited on glass substrates at 523K for x=0.00, 0.10, 0.20, and 0.40 compositions.
2. Energy dispersive X-ray analysis confirmed the presence of Cd, S, and Co in the appropriate stoichiometric ratios.
3. X-ray diffraction showed all films were amorphous in nature as deposited.
4. The optical band gap decreased from 2.54 eV to 2.40 eV
This document summarizes the synthesis and characterization of cadmium sulfide (CdS) nanorods doped with copper (Cu) for application in photonic devices. X-ray diffraction analysis showed that the as-prepared CdS:Cu nanorods were a mixture of hexagonal and cubic phases, with preferential growth of the (100) plane. Transmission electron microscopy images revealed garland-like nanorod structures consisting of cubic and hexagonal particles, with hexagonal particles confirming the hexagonal phase of CdS. The CdS:Cu nanorods exhibited a red shift in absorption compared to undoped CdS, indicating quantum confinement effects due to Cu doping.
Study Of Structural, Morphological And Optical Properties Of Pure CdO And Ag:...IOSRJAP
The document summarizes a study of the structural, morphological, and optical properties of pure cadmium oxide (CdO) thin films and CdO thin films doped with silver (Ag) at concentrations of 2.5%, 5%, 10%, and 15%. The films were prepared by a sol-gel method and analyzed using X-ray diffraction (XRD), UV-visible spectroscopy, and scanning probe microscopy (SPM). The results showed that doping CdO with Ag led to changes in the crystal structure, a decrease in the optical band gap, and changes in surface roughness and grain size compared to pure CdO films. In particular, higher Ag doping concentrations of 5%, 10%, and 15% resulted in
Optical and Morphological Characterization of BaSeThinFilms Synthesized via C...IOSR Journals
Barium selinide (BaSe) thin films were deposited onto glass substrate via chemical bath deposition (CBD) method. The effect of deposition time on the thin film formation mechanism has been studied to understand the optimum conditions for synthesis process. The phase identification and surface morphology of thin coated films were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively while the optical characterizations were conducted by means of ultraviolet visible (UV- Vis) spectroscopy. XRD study confirms the polycrystalline hexagonal structure of the thin films. The XRD peaks at 2θ =23.84° and 2θ = 23.86o showed the preferential orientation along the (021) and (201)plane with deposition time 20 hours and 22 hours respectively, whereas the major peak at (111) was obtained with a deposition time of 24 hours. With the increase in deposition time up to 24 hours, the film gradually grew thicker along with the fine increase in the grain size. The direct optical band gap of the films was measured to be varied from 1.33 to 3.37 eV.
An Investigation of SILAR Grown Cobalt Selenide Thin Films IIJSRJournal
Nowadays, several deposition techniques have been used to produce thin film materials. The obtained films were characterized by using different tools. These semiconductor materials could be employed in solar cell, laser devices and opto-electronic devices. The main objective of this work is to produce cobalt selenide thin films through successive ionic layer adsorption and reaction method. Advantages of this method include simple procedures, inexpensive equipment, it does not need expensive vacuum system and high quality substrate. During the deposition process, the films were deposited onto soda lime glass under various anionic bath immersion times. The properties of the films were studied for the first time via field emission scanning electron microscopy (FESEM) and UV-visible spectrophotometer. Based on the FESEM analysis, uniform morphology could be observed for the sample produced for 30 seconds (anionic immersion time). The band gap was about 2.6 eV and the optical transmission increased in the visible region could be detected for these samples.
ELECTRICAL AND STRUCTURAL PROPERTIES OF ZnSe THIN FILMS BY ELECTRODEPOSITION ...IKHIOYA IMOSOBOMEH LUCKY
The document summarizes research on producing zinc selenide (ZnSe) thin films through an electrodeposition technique. X-ray diffraction analysis showed the films had a cubic structure and preferred orientation along the (111) plane. Optical analysis found the band gap energy was between 2.1-2.3 eV. Electrical measurements showed the films had high resistivity, making ZnSe suitable as a buffer layer in thin film technologies. Overall, the research aimed to characterize ZnSe thin films produced through an inexpensive electrodeposition method for potential optoelectronic and photovoltaic device applications.
Thin films of cadmium sulphide have been
successfully deposited by chemical bath deposition (CBD)
technique using a mixed aqueous solution of cadmium
sulphate, thiourea, and triethylamine. The films were
characterized using a variety of techniques. Powder X-ray
diffraction analysis shows that the as-deposited thin film has
the hexagonal (wurtzite) structure. Scanning electron
microscope (SEM) micrographs show the film surface consists
of clusters with a globular surface morphology. Energy
dispersive X-ray diffraction (EDAX) analysis confirmed the
film to be consistent with the formation of cadmium sulphide
on silica glass slide. The band gap, determined from optical
absorption spectroscopy, was 2.42 eV which is consistent with
other published results.
Structural, Optical and Electrical Studies on Spray Deposited Mercury Doped C...ijrap
Thin films of cadmium sulphide have been prepared using home built spray pyrolysis unit on glass substrate at 400 C. Aqueous solutions of cadmium chloride and thiourea were used for the cadmium
sulphide (CdS) films and different proportions by weight/volume of mercury II chloride was used for doping Hg onto cadmium sulphide (Cd1-xHgxS) films. The films obtained are having continuous, smooth surface with good transmittance. The thickness of all films is of the order of 320 nm. Determination of the crystalline nature has been done using XRD pattern. The effect of Hg on the surface morphology of CdS film has been studied by Scanning Electron Microscopy. The optical band gap has been calculated using the data from transmission spectra. Resistance before and after doping with Hg is also presented in the paper.
This document summarizes the synthesis and characterization of cadmium sulfide (CdS) nanorods doped with copper (Cu) for application in photonic devices. X-ray diffraction analysis showed that the as-prepared CdS:Cu nanorods were a mixture of hexagonal and cubic phases, with preferential growth of the (100) plane. Transmission electron microscopy images revealed garland-like nanorod structures consisting of cubic and hexagonal particles, with hexagonal particles confirming the hexagonal phase of CdS. The CdS:Cu nanorods exhibited a red shift in absorption compared to undoped CdS, indicating quantum confinement effects due to Cu doping.
Study Of Structural, Morphological And Optical Properties Of Pure CdO And Ag:...IOSRJAP
The document summarizes a study of the structural, morphological, and optical properties of pure cadmium oxide (CdO) thin films and CdO thin films doped with silver (Ag) at concentrations of 2.5%, 5%, 10%, and 15%. The films were prepared by a sol-gel method and analyzed using X-ray diffraction (XRD), UV-visible spectroscopy, and scanning probe microscopy (SPM). The results showed that doping CdO with Ag led to changes in the crystal structure, a decrease in the optical band gap, and changes in surface roughness and grain size compared to pure CdO films. In particular, higher Ag doping concentrations of 5%, 10%, and 15% resulted in
Optical and Morphological Characterization of BaSeThinFilms Synthesized via C...IOSR Journals
Barium selinide (BaSe) thin films were deposited onto glass substrate via chemical bath deposition (CBD) method. The effect of deposition time on the thin film formation mechanism has been studied to understand the optimum conditions for synthesis process. The phase identification and surface morphology of thin coated films were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively while the optical characterizations were conducted by means of ultraviolet visible (UV- Vis) spectroscopy. XRD study confirms the polycrystalline hexagonal structure of the thin films. The XRD peaks at 2θ =23.84° and 2θ = 23.86o showed the preferential orientation along the (021) and (201)plane with deposition time 20 hours and 22 hours respectively, whereas the major peak at (111) was obtained with a deposition time of 24 hours. With the increase in deposition time up to 24 hours, the film gradually grew thicker along with the fine increase in the grain size. The direct optical band gap of the films was measured to be varied from 1.33 to 3.37 eV.
An Investigation of SILAR Grown Cobalt Selenide Thin Films IIJSRJournal
Nowadays, several deposition techniques have been used to produce thin film materials. The obtained films were characterized by using different tools. These semiconductor materials could be employed in solar cell, laser devices and opto-electronic devices. The main objective of this work is to produce cobalt selenide thin films through successive ionic layer adsorption and reaction method. Advantages of this method include simple procedures, inexpensive equipment, it does not need expensive vacuum system and high quality substrate. During the deposition process, the films were deposited onto soda lime glass under various anionic bath immersion times. The properties of the films were studied for the first time via field emission scanning electron microscopy (FESEM) and UV-visible spectrophotometer. Based on the FESEM analysis, uniform morphology could be observed for the sample produced for 30 seconds (anionic immersion time). The band gap was about 2.6 eV and the optical transmission increased in the visible region could be detected for these samples.
ELECTRICAL AND STRUCTURAL PROPERTIES OF ZnSe THIN FILMS BY ELECTRODEPOSITION ...IKHIOYA IMOSOBOMEH LUCKY
The document summarizes research on producing zinc selenide (ZnSe) thin films through an electrodeposition technique. X-ray diffraction analysis showed the films had a cubic structure and preferred orientation along the (111) plane. Optical analysis found the band gap energy was between 2.1-2.3 eV. Electrical measurements showed the films had high resistivity, making ZnSe suitable as a buffer layer in thin film technologies. Overall, the research aimed to characterize ZnSe thin films produced through an inexpensive electrodeposition method for potential optoelectronic and photovoltaic device applications.
Thin films of cadmium sulphide have been
successfully deposited by chemical bath deposition (CBD)
technique using a mixed aqueous solution of cadmium
sulphate, thiourea, and triethylamine. The films were
characterized using a variety of techniques. Powder X-ray
diffraction analysis shows that the as-deposited thin film has
the hexagonal (wurtzite) structure. Scanning electron
microscope (SEM) micrographs show the film surface consists
of clusters with a globular surface morphology. Energy
dispersive X-ray diffraction (EDAX) analysis confirmed the
film to be consistent with the formation of cadmium sulphide
on silica glass slide. The band gap, determined from optical
absorption spectroscopy, was 2.42 eV which is consistent with
other published results.
Structural, Optical and Electrical Studies on Spray Deposited Mercury Doped C...ijrap
Thin films of cadmium sulphide have been prepared using home built spray pyrolysis unit on glass substrate at 400 C. Aqueous solutions of cadmium chloride and thiourea were used for the cadmium
sulphide (CdS) films and different proportions by weight/volume of mercury II chloride was used for doping Hg onto cadmium sulphide (Cd1-xHgxS) films. The films obtained are having continuous, smooth surface with good transmittance. The thickness of all films is of the order of 320 nm. Determination of the crystalline nature has been done using XRD pattern. The effect of Hg on the surface morphology of CdS film has been studied by Scanning Electron Microscopy. The optical band gap has been calculated using the data from transmission spectra. Resistance before and after doping with Hg is also presented in the paper.
Characterization Studies of CdS Nanocrystalline Film Deposited on Teflon Subs...IJLT EMAS
In this article, different substrates for deposition of
CdS material have been discussed. Till date glass, mica, quartz,
ceramic, etc. are commonly employed substrates in thin film
growth. In the present work, CdS is deposited on Teflon
substrate by chemical bath deposition (CBD) method. Also the
films were deposited on different substrates like glass, copper
and zinc and compared with those prepared on Teflon substrate.
The films prepared on Teflon substrate were uniform, stable and
also showed good radiating property. These films were further
characterized by UV-VIS absorption spectral studies, SEM and
EDS studies.
OPTICAL BEHAVIOUR OF SYNTHESIZED ZNO NANOTABLETS AND ITS TRANSFORMED NANORODS...antjjournal
We are reporting the preparation of ZnO nanotablets at relatively low temperature (1500C) using zinc acetate [Zn(Ac)2], NaOH, cetyltrimethylammonium bromide (CTAB) by solvothermal method. By adjusting
the molar ratio of the reactants we obtained nanorods and we also obtained the variation of the dimension
of the nanorods using hydrazine hydrate as capping reagent. The prepared samples were morphologically
recognized as well crystallized. The average diameter of the ZnO nanotablets were ranging from 500 to 600 nm and the average thickness of the nanotablets were ranging from 85 to 90 nm. The length of ZnO nanorods were ranging from 300 to several micrometers and breadth of the ZnO nanorods were ranging from 80 to 160 nm. The optical properties of the prepared materials have also been studied with the exhibition of its interesting behavior.
Optimization of optical properties of annealed cadmium selenide (cdse) thin f...Alexander Decker
1) Cadmium selenide thin films were deposited on glass substrates at room temperature (25°C) and a higher temperature (74°C) using a chemical bath deposition technique with sodium selenosulphite as the selenium source.
2) The films were annealed at different temperatures and their optical properties like transmittance, reflectance, and band gap were analyzed using spectroscopy.
3) The results showed that the films deposited at room temperature had higher band gaps than those deposited at 74°C. Transmittance increased with lower annealing temperatures while absorbance and reflectance increased with higher annealing temperatures.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Morphological and Optical Study of Sol-Gel SpinCoated Nanostructured CdSThin ...iosrjce
Nanostructured CdS thin films of different thicknesses were deposited on a cleaned glass substrate
using sol-gel spin coating technique. CdS thin films were prepared using cadmium acetate as cadmium source
and thiourea as sulfur source. The Morphological, chemical composition, and optical properties of the spin- coated
CdS thin film were studied using field emission- scanning electron microscopy (FE-SEM), Energy dispersive X –ray
(EDX) spectroscopy, and a UV-Vis-NIR spectrophotometer.The morphological results revealed that the films consist
of agglomerated spherical CdS nanoparticles with diameter < 20 nm, which distributed uniformly on the substrate
surface.The films show high transmittance > 90% and very strong absorption edge at 295 nm.The absorption edge
shifts towards longer wavelength as the film thickness increased.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
The document summarizes research on the physical properties of II-VI ternary semiconductor alloys of sulphides, selenides, and tellurides. It first provides background on the potential of these materials for solar cells due to their direct bandgaps and high optical absorption. It then examines the refractive index, optical polarizability, absorption coefficient, and bandgap of various ternary alloys, including CdSxSe1-x, Zn1-xHgxTe, CdSe1-xTex, ZnxCd1-xS, and Pb1-xSnxTe. Calculations of these properties at different compositions are performed using additivity rules and quadratic expressions. Results are presented
Effect of Annealing On the Structural and Optical Properties of Cdsexs1-Xthin...IOSR Journals
The document summarizes a study on the effect of annealing on the structural and optical properties of CdSexS1-x thin films with varying compositions of x (0, 0.4, 0.8, 1). X-ray diffraction analysis showed that annealing increased the crystallinity and grain size of the films and decreased dislocation density and strain. Optical analysis found that annealing increased transmittance and decreased absorbance. The optical band gap was found to decrease with increasing selenium concentration but increase with annealing temperature at x=1 and remain constant at x=0.4. Overall, annealing was found to improve the structural and optical properties of the CdSexS1-x thin films.
Optimal growth and characterization of cobalt sulphide thin films fabricated ...Alexander Decker
The document summarizes research on growing and characterizing cobalt sulfide thin films using chemical bath deposition. Key findings include:
1) Cobalt sulfide thin films were successfully deposited on glass from an aqueous solution containing cobalt chloride, thiourea, ammonia, and EDTA.
2) The films showed high absorbance of UV light and low transmittance in the UV region, indicating they could be used in applications requiring UV filtering.
3) Band gap energy of the films was found to be 1.72 eV, making the material suitable for photovoltaic and optoelectronic devices.
Effect of Post Annealing on Structural and Optical Propertie of Sno2 Thin Fil...IOSR Journals
This document discusses the effect of post-annealing on the structural and optical properties of tin oxide (SnO2) thin films deposited by DC magnetron sputtering. SnO2 thin films were deposited on glass substrates at 200°C and then annealed at temperatures of 300°C, 400°C, and 500°C for 1 hour. X-ray diffraction analysis showed the films had a polycrystalline tetragonal structure. Annealing improved the crystallinity and grain size of the films. Optical transmission was found to increase with annealing temperature up to 400°C. Band gap, Urbach energy, and optical constants like refractive index and dielectric constants were calculated from optical measurements and followed expected trends with
Lithium sodium bismuth borate glasses-doped with trivalent dysprosium (Dy3+) ions (LSBiB) have been
prepared by conventional melt-quenching technique and characterized by structural, thermal and spectroscopic
measurements. XRD pattern of the host glass confirms its amorphous nature. Morphological and elemental
analysis has also been carried out for Dy3+doped LSBiB glass matrix. FTIR spectral analysis confirms the glass
formation of the host glass. Optical absorption spectral analysis has been carried out for 0.8 mol% Dy3+ doped
LSBiB glass sample. Well defined optical absorption bands are assigned with corresponding electronic
transitions. Photoluminescence spectra shows two prominent emission bands centered at 482 nm and 575 nm
corresponds to the 4F9/2 → 6H15/2 and 4F9/2 → 6H13/2 respectively under the excitation of 452 nm. Among all the
concentrations of Dy3+ ions, at 0.8 mol% Dy3+ contained glass sample exhibits prominent yellow emission at
575 nm. Lifetime decay dynamics have been systematically analyzed for all the glasses, higher lifetime is found
to be 0.47 ms for 0.8 mol% Dy3+ ions doped glass. From the photoluminescence analysis, Dy3+ contained glass
samples could be suggested as potential yellow luminescent glass matrix for several photonic device
applications.
This document summarizes research on cobalt selenide thin films grown using the chemical bath deposition method and the effects of post-deposition annealing. Cobalt selenide films were deposited at varying thicknesses and then annealed at temperatures from 100 to 250°C. The films were characterized using SEM, EDAX, and XRD. SEM images showed annealing increased grain size and densified the films. XRD analysis confirmed the hexagonal crystal structure and showed annealing increased average crystallite size to 30.61 nm. Film thickness initially increased with concentration up to 0.25M then decreased, and increased with annealing temperatures up to 200°C due to increased grain size. Overall, annealing was shown to improve the structural and
K2O - CdO - B2O3 – SiO2glasses containing different concentrations of MnO2 have been prepared. The Physical properties of the glasses are studied from their density. The studies have been analysed in the light of different oxidation states of manganese ion with the aid of the data from optical absorption. The analysis shows that manganese ions exist mainly in Mn2+ state, occupy tetrahedral positions and increase the insulating strength of the glass if MnO2 is present in smaller concentrations.
Optical Properties of Nanostructured Cerium Oxide Thin Films by Pulsed Laser ...IRJET Journal
Cerium oxide thin films were deposited on quartz substrates using pulsed laser deposition. X-ray diffraction was used to characterize the structural properties of the films deposited at different substrate temperatures. The film deposited at 303K was amorphous, while the film deposited at 523K was quasi-crystalline. Increasing the substrate temperature to 923K resulted in a polycrystalline film. Optical properties were studied using UV-visible spectroscopy, which showed the films were highly transparent in the visible region with low reflectance in ultraviolet. Band gap was found to decrease with increasing film thickness.
Dye Sensitized Solar Cells Incorporated with Tio2 -ZnO NanoparticlesScientific Review SR
This document summarizes a study that incorporated zinc oxide (ZnO) nanoparticles into dye-sensitized solar cells (DSSCs) to improve their photovoltaic performance. DSSCs were fabricated with TiO2 films that were coated with different numbers of ZnO layers using successive ionic layer adsorption and reaction (SILAR). The cells were tested under illumination and the best performance was achieved with two SILAR cycles of ZnO, with a power conversion efficiency of 0.0064%, over double that of cells without ZnO. More ZnO layers led to lower efficiencies due to increased recombination and reduced light absorption, showing an optimal thickness was achieved with two SILAR cycles.
IOSR Journal of Applied Physics (IOSR-JAP) is an open access international journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
IRJET- A Review on Sputtered Zirconium based Thin FilmsIRJET Journal
The document summarizes research on sputtered zirconium-based thin films. It reviews 5 studies that deposited zirconium oxynitride films using various sputtering techniques like RF magnetron sputtering and analyzed the films' properties. The studies found that deposition parameters like temperature, gas flow rates, and power affected the films' crystal structure, morphology, hardness, and optical properties. Substrate materials included stainless steel, silicon, and glass. Properties analyzed included crystal structure, grain size, roughness, thickness, band gap, and corrosion resistance. Together the studies demonstrated how sputtering can be used to deposit zirconium oxynitride thin films and influence their resulting characteristics.
Study of Annealing Effect on the Some Physical Properties of Nanostructured T...sarmad
Ali A.Yousif ● , Sarmad S. Al-Obaidi ●●
Abstract
Nanostructured Titanium Dioxide (TiO2) thin films were prepared by pulsed
laser deposition (PLD) on the glass substrates. The effects of different annealing
temperature (400, 500 and 600 °C) towards the some physical properties such as
structural, morphological and optical have been studied. From X-ray diffraction
result, the crystallinity of TiO2 thin films improved at higher annealing
temperature. It also could be observed that the rutile phase start to exist at
annealing temperatures of 500 °C and 600 °C. The Full Width at Half
Maximum (FWHM) of the (101) peaks of these films decreases from 0.450° to
0.301° with increasing of annealing temperature. AFM measurements confirmed
that the films grown by this technique have good crystalline and homogeneous
surface. The Root Mean Square (RMS) value of thin films surface roughness
increased with increasing of the annealing temperature. From UV-VIS
spectrophotometer measurements, the optical transmission results shows that the transmission over than ~65% in the near-infrared region which decrease with the increasing of annealing temperatures. The allowed indirect optical band gap of the films was estimated to be in the range from 3.49 to 3.1 eV. The allowed direct band gap was found to decrease from 3.74 eV to 3.55 eV with the increase of annealing temperature. The refractive index of the films was found from 2.27 -2.98 at 550nm. The extinction coefficient, real and imaginary parts of the dielectric constant increase with annealing temperature.
Invited lecture of the Simposium N "Surface Engineering - functional coatings and modified surfaces" at the XIII SBPMat (Brazilian MRS) meeting, in João Pessoa (Brazil). The lecture took place on September 30th, 2014.
The speaker was Professor Christoph Genzel, from the Helmholtz-Zentrum Berlin für Materialien und Energie (HZB), in Germany, where he heads the Department of Microstructure and Residual Stress Analysis and he coordinates a group of diffraction and scattering. Genzel is also Associate Professor at the Technische Universität Berlin.
STRUCTURAL, OPTICAL AND ELECTRICAL STUDIES ON SPRAY DEPOSITED MERCURY DOPED C...ijrap
Thin films of cadmium sulphide have been prepared using home built spray pyrolysis unit on glass
substrate at 400 C. Aqueous solutions of cadmium chloride and thiourea were used for the cadmium
sulphide (CdS) films and different proportions by weight/volume of mercury II chloride was used for
doping Hg onto cadmium sulphide (Cd1-xHgxS) films. The films obtained are having continuous, smooth
surface with good transmittance. The thickness of all films is of the order of 320 nm. Determination of the
crystalline nature has been done using XRD pattern. The effect of Hg on the surface morphology of CdS
film has been studied by Scanning Electron Microscopy. The optical band gap has been calculated using
the data from transmission spectra. Resistance before and after doping with Hg is also presented in the
paper.
IRJET - Characterization of Bivalent Zn (II) and Cd (II) Nanoparticles / ...IRJET Journal
This document characterizes bivalent zinc (II) and cadmium (II) nanoparticles and nanocomposites using X-ray diffraction (XRD). XRD and energy dispersive X-ray spectroscopy (EDS) show that ZnS nanoparticles have a hexagonal crystal structure. CdS-ZnS nanocomposites contain both cubic CdS and hexagonal ZnS nanoparticles in close contact. ZnS/CdS core-shell nanoparticles contain a ZnS core and thin CdS shell, while CdS/ZnS contain a CdS core and thin ZnS shell.
The document summarizes research on developing novel thin film cadmium telluride (CdTe) solar cells with an ultra-thin oxygenated cadmium sulfide (CdS:O) window layer deposited by magnetron sputtering. Key points discussed include:
1) Conventional CdS window layers have limitations like a mismatch with CdTe that increases defects, while CdS:O has a better lattice match and higher bandgap allowing more light to reach the CdTe layer.
2) Thin films of ZnO:Sn, CdS:O, and CdTe were deposited by sputtering and characterized, with the CdS:O showing nanocrystalline grains, bandgaps tun
Characterization Studies of CdS Nanocrystalline Film Deposited on Teflon Subs...IJLT EMAS
In this article, different substrates for deposition of
CdS material have been discussed. Till date glass, mica, quartz,
ceramic, etc. are commonly employed substrates in thin film
growth. In the present work, CdS is deposited on Teflon
substrate by chemical bath deposition (CBD) method. Also the
films were deposited on different substrates like glass, copper
and zinc and compared with those prepared on Teflon substrate.
The films prepared on Teflon substrate were uniform, stable and
also showed good radiating property. These films were further
characterized by UV-VIS absorption spectral studies, SEM and
EDS studies.
OPTICAL BEHAVIOUR OF SYNTHESIZED ZNO NANOTABLETS AND ITS TRANSFORMED NANORODS...antjjournal
We are reporting the preparation of ZnO nanotablets at relatively low temperature (1500C) using zinc acetate [Zn(Ac)2], NaOH, cetyltrimethylammonium bromide (CTAB) by solvothermal method. By adjusting
the molar ratio of the reactants we obtained nanorods and we also obtained the variation of the dimension
of the nanorods using hydrazine hydrate as capping reagent. The prepared samples were morphologically
recognized as well crystallized. The average diameter of the ZnO nanotablets were ranging from 500 to 600 nm and the average thickness of the nanotablets were ranging from 85 to 90 nm. The length of ZnO nanorods were ranging from 300 to several micrometers and breadth of the ZnO nanorods were ranging from 80 to 160 nm. The optical properties of the prepared materials have also been studied with the exhibition of its interesting behavior.
Optimization of optical properties of annealed cadmium selenide (cdse) thin f...Alexander Decker
1) Cadmium selenide thin films were deposited on glass substrates at room temperature (25°C) and a higher temperature (74°C) using a chemical bath deposition technique with sodium selenosulphite as the selenium source.
2) The films were annealed at different temperatures and their optical properties like transmittance, reflectance, and band gap were analyzed using spectroscopy.
3) The results showed that the films deposited at room temperature had higher band gaps than those deposited at 74°C. Transmittance increased with lower annealing temperatures while absorbance and reflectance increased with higher annealing temperatures.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Morphological and Optical Study of Sol-Gel SpinCoated Nanostructured CdSThin ...iosrjce
Nanostructured CdS thin films of different thicknesses were deposited on a cleaned glass substrate
using sol-gel spin coating technique. CdS thin films were prepared using cadmium acetate as cadmium source
and thiourea as sulfur source. The Morphological, chemical composition, and optical properties of the spin- coated
CdS thin film were studied using field emission- scanning electron microscopy (FE-SEM), Energy dispersive X –ray
(EDX) spectroscopy, and a UV-Vis-NIR spectrophotometer.The morphological results revealed that the films consist
of agglomerated spherical CdS nanoparticles with diameter < 20 nm, which distributed uniformly on the substrate
surface.The films show high transmittance > 90% and very strong absorption edge at 295 nm.The absorption edge
shifts towards longer wavelength as the film thickness increased.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
The document summarizes research on the physical properties of II-VI ternary semiconductor alloys of sulphides, selenides, and tellurides. It first provides background on the potential of these materials for solar cells due to their direct bandgaps and high optical absorption. It then examines the refractive index, optical polarizability, absorption coefficient, and bandgap of various ternary alloys, including CdSxSe1-x, Zn1-xHgxTe, CdSe1-xTex, ZnxCd1-xS, and Pb1-xSnxTe. Calculations of these properties at different compositions are performed using additivity rules and quadratic expressions. Results are presented
Effect of Annealing On the Structural and Optical Properties of Cdsexs1-Xthin...IOSR Journals
The document summarizes a study on the effect of annealing on the structural and optical properties of CdSexS1-x thin films with varying compositions of x (0, 0.4, 0.8, 1). X-ray diffraction analysis showed that annealing increased the crystallinity and grain size of the films and decreased dislocation density and strain. Optical analysis found that annealing increased transmittance and decreased absorbance. The optical band gap was found to decrease with increasing selenium concentration but increase with annealing temperature at x=1 and remain constant at x=0.4. Overall, annealing was found to improve the structural and optical properties of the CdSexS1-x thin films.
Optimal growth and characterization of cobalt sulphide thin films fabricated ...Alexander Decker
The document summarizes research on growing and characterizing cobalt sulfide thin films using chemical bath deposition. Key findings include:
1) Cobalt sulfide thin films were successfully deposited on glass from an aqueous solution containing cobalt chloride, thiourea, ammonia, and EDTA.
2) The films showed high absorbance of UV light and low transmittance in the UV region, indicating they could be used in applications requiring UV filtering.
3) Band gap energy of the films was found to be 1.72 eV, making the material suitable for photovoltaic and optoelectronic devices.
Effect of Post Annealing on Structural and Optical Propertie of Sno2 Thin Fil...IOSR Journals
This document discusses the effect of post-annealing on the structural and optical properties of tin oxide (SnO2) thin films deposited by DC magnetron sputtering. SnO2 thin films were deposited on glass substrates at 200°C and then annealed at temperatures of 300°C, 400°C, and 500°C for 1 hour. X-ray diffraction analysis showed the films had a polycrystalline tetragonal structure. Annealing improved the crystallinity and grain size of the films. Optical transmission was found to increase with annealing temperature up to 400°C. Band gap, Urbach energy, and optical constants like refractive index and dielectric constants were calculated from optical measurements and followed expected trends with
Lithium sodium bismuth borate glasses-doped with trivalent dysprosium (Dy3+) ions (LSBiB) have been
prepared by conventional melt-quenching technique and characterized by structural, thermal and spectroscopic
measurements. XRD pattern of the host glass confirms its amorphous nature. Morphological and elemental
analysis has also been carried out for Dy3+doped LSBiB glass matrix. FTIR spectral analysis confirms the glass
formation of the host glass. Optical absorption spectral analysis has been carried out for 0.8 mol% Dy3+ doped
LSBiB glass sample. Well defined optical absorption bands are assigned with corresponding electronic
transitions. Photoluminescence spectra shows two prominent emission bands centered at 482 nm and 575 nm
corresponds to the 4F9/2 → 6H15/2 and 4F9/2 → 6H13/2 respectively under the excitation of 452 nm. Among all the
concentrations of Dy3+ ions, at 0.8 mol% Dy3+ contained glass sample exhibits prominent yellow emission at
575 nm. Lifetime decay dynamics have been systematically analyzed for all the glasses, higher lifetime is found
to be 0.47 ms for 0.8 mol% Dy3+ ions doped glass. From the photoluminescence analysis, Dy3+ contained glass
samples could be suggested as potential yellow luminescent glass matrix for several photonic device
applications.
This document summarizes research on cobalt selenide thin films grown using the chemical bath deposition method and the effects of post-deposition annealing. Cobalt selenide films were deposited at varying thicknesses and then annealed at temperatures from 100 to 250°C. The films were characterized using SEM, EDAX, and XRD. SEM images showed annealing increased grain size and densified the films. XRD analysis confirmed the hexagonal crystal structure and showed annealing increased average crystallite size to 30.61 nm. Film thickness initially increased with concentration up to 0.25M then decreased, and increased with annealing temperatures up to 200°C due to increased grain size. Overall, annealing was shown to improve the structural and
K2O - CdO - B2O3 – SiO2glasses containing different concentrations of MnO2 have been prepared. The Physical properties of the glasses are studied from their density. The studies have been analysed in the light of different oxidation states of manganese ion with the aid of the data from optical absorption. The analysis shows that manganese ions exist mainly in Mn2+ state, occupy tetrahedral positions and increase the insulating strength of the glass if MnO2 is present in smaller concentrations.
Optical Properties of Nanostructured Cerium Oxide Thin Films by Pulsed Laser ...IRJET Journal
Cerium oxide thin films were deposited on quartz substrates using pulsed laser deposition. X-ray diffraction was used to characterize the structural properties of the films deposited at different substrate temperatures. The film deposited at 303K was amorphous, while the film deposited at 523K was quasi-crystalline. Increasing the substrate temperature to 923K resulted in a polycrystalline film. Optical properties were studied using UV-visible spectroscopy, which showed the films were highly transparent in the visible region with low reflectance in ultraviolet. Band gap was found to decrease with increasing film thickness.
Dye Sensitized Solar Cells Incorporated with Tio2 -ZnO NanoparticlesScientific Review SR
This document summarizes a study that incorporated zinc oxide (ZnO) nanoparticles into dye-sensitized solar cells (DSSCs) to improve their photovoltaic performance. DSSCs were fabricated with TiO2 films that were coated with different numbers of ZnO layers using successive ionic layer adsorption and reaction (SILAR). The cells were tested under illumination and the best performance was achieved with two SILAR cycles of ZnO, with a power conversion efficiency of 0.0064%, over double that of cells without ZnO. More ZnO layers led to lower efficiencies due to increased recombination and reduced light absorption, showing an optimal thickness was achieved with two SILAR cycles.
IOSR Journal of Applied Physics (IOSR-JAP) is an open access international journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
IRJET- A Review on Sputtered Zirconium based Thin FilmsIRJET Journal
The document summarizes research on sputtered zirconium-based thin films. It reviews 5 studies that deposited zirconium oxynitride films using various sputtering techniques like RF magnetron sputtering and analyzed the films' properties. The studies found that deposition parameters like temperature, gas flow rates, and power affected the films' crystal structure, morphology, hardness, and optical properties. Substrate materials included stainless steel, silicon, and glass. Properties analyzed included crystal structure, grain size, roughness, thickness, band gap, and corrosion resistance. Together the studies demonstrated how sputtering can be used to deposit zirconium oxynitride thin films and influence their resulting characteristics.
Study of Annealing Effect on the Some Physical Properties of Nanostructured T...sarmad
Ali A.Yousif ● , Sarmad S. Al-Obaidi ●●
Abstract
Nanostructured Titanium Dioxide (TiO2) thin films were prepared by pulsed
laser deposition (PLD) on the glass substrates. The effects of different annealing
temperature (400, 500 and 600 °C) towards the some physical properties such as
structural, morphological and optical have been studied. From X-ray diffraction
result, the crystallinity of TiO2 thin films improved at higher annealing
temperature. It also could be observed that the rutile phase start to exist at
annealing temperatures of 500 °C and 600 °C. The Full Width at Half
Maximum (FWHM) of the (101) peaks of these films decreases from 0.450° to
0.301° with increasing of annealing temperature. AFM measurements confirmed
that the films grown by this technique have good crystalline and homogeneous
surface. The Root Mean Square (RMS) value of thin films surface roughness
increased with increasing of the annealing temperature. From UV-VIS
spectrophotometer measurements, the optical transmission results shows that the transmission over than ~65% in the near-infrared region which decrease with the increasing of annealing temperatures. The allowed indirect optical band gap of the films was estimated to be in the range from 3.49 to 3.1 eV. The allowed direct band gap was found to decrease from 3.74 eV to 3.55 eV with the increase of annealing temperature. The refractive index of the films was found from 2.27 -2.98 at 550nm. The extinction coefficient, real and imaginary parts of the dielectric constant increase with annealing temperature.
Invited lecture of the Simposium N "Surface Engineering - functional coatings and modified surfaces" at the XIII SBPMat (Brazilian MRS) meeting, in João Pessoa (Brazil). The lecture took place on September 30th, 2014.
The speaker was Professor Christoph Genzel, from the Helmholtz-Zentrum Berlin für Materialien und Energie (HZB), in Germany, where he heads the Department of Microstructure and Residual Stress Analysis and he coordinates a group of diffraction and scattering. Genzel is also Associate Professor at the Technische Universität Berlin.
STRUCTURAL, OPTICAL AND ELECTRICAL STUDIES ON SPRAY DEPOSITED MERCURY DOPED C...ijrap
Thin films of cadmium sulphide have been prepared using home built spray pyrolysis unit on glass
substrate at 400 C. Aqueous solutions of cadmium chloride and thiourea were used for the cadmium
sulphide (CdS) films and different proportions by weight/volume of mercury II chloride was used for
doping Hg onto cadmium sulphide (Cd1-xHgxS) films. The films obtained are having continuous, smooth
surface with good transmittance. The thickness of all films is of the order of 320 nm. Determination of the
crystalline nature has been done using XRD pattern. The effect of Hg on the surface morphology of CdS
film has been studied by Scanning Electron Microscopy. The optical band gap has been calculated using
the data from transmission spectra. Resistance before and after doping with Hg is also presented in the
paper.
IRJET - Characterization of Bivalent Zn (II) and Cd (II) Nanoparticles / ...IRJET Journal
This document characterizes bivalent zinc (II) and cadmium (II) nanoparticles and nanocomposites using X-ray diffraction (XRD). XRD and energy dispersive X-ray spectroscopy (EDS) show that ZnS nanoparticles have a hexagonal crystal structure. CdS-ZnS nanocomposites contain both cubic CdS and hexagonal ZnS nanoparticles in close contact. ZnS/CdS core-shell nanoparticles contain a ZnS core and thin CdS shell, while CdS/ZnS contain a CdS core and thin ZnS shell.
The document summarizes research on developing novel thin film cadmium telluride (CdTe) solar cells with an ultra-thin oxygenated cadmium sulfide (CdS:O) window layer deposited by magnetron sputtering. Key points discussed include:
1) Conventional CdS window layers have limitations like a mismatch with CdTe that increases defects, while CdS:O has a better lattice match and higher bandgap allowing more light to reach the CdTe layer.
2) Thin films of ZnO:Sn, CdS:O, and CdTe were deposited by sputtering and characterized, with the CdS:O showing nanocrystalline grains, bandgaps tun
The document discusses electrodeposited cadmium sulfide (CdS) as the n-type semiconductor layer in copper indium gallium selenide (CIGS) thin film solar cells. Figure a-d show the visual appearance, surface morphology, transmittance, and crystal structure of the CdS films. Electrodeposition produces hexagonal CdS at room temperature with no post-treatment, and shows higher photoactivity than chemically bath deposited CdS. Photoelectrochemical measurements indicate that electrodeposited CdS on CIGS enhances light absorption and electron-hole separation compared to bare CIGS. The electrodeposition technique is advantageous as it reuses electrolytes and produces less toxic waste than chemical
Influence of Manganese doping on Structural, optical and ethanol sensing of S...IRJET Journal
This document summarizes research on the influence of manganese doping on the structural, optical, and ethanol sensing properties of copper oxide thin films synthesized using successive ion layer adsorption and reaction technique. Key findings include:
- X-ray diffraction analysis showed manganese doping reduced grain size up to 5% doping due to increased microstrain, beyond which grain size increased.
- Optical studies found the band gap increased with doping up to 5% due to the Burstein-Moss effect, then decreased with further doping likely due to excess manganese in interstitial sites.
- The 5% doped film exhibited the highest sensitivity of 87% for detecting 1500 ppm ethanol at
Effect of zinc on structural and some optical properties of cd s thin filmsAlexander Decker
This document summarizes research on the structural and optical properties of cadmium sulfide (CdS) thin films doped with varying concentrations of zinc (Zn). X-ray diffraction analysis showed that all films had a hexagonal structure and were polycrystalline. Grain size decreased with increasing Zn concentration, while surface roughness decreased based on atomic force microscopy. Optical analysis found that transmittance increased with Zn concentration, as did the optical band gap. Increasing the Zn dopant concentration improved some structural and optical properties of the CdS thin films.
Influence of Synthesizing Temperatures on the Crystallinity, Morphology and B...AI Publications
CdSe thin films were deposited using Chemical Bath Deposition (CBD) by maintaining the bath at 20 °C, 40 °C, 60 °C and 80 °C temperatures. The thin films were deposited on ordinary glass substrates then characterized for their crystallinity, morphological and optical properties. From the X-ray Diffraction (XRD) analysis; it was revealed that there was a significant difference in crystallinity and the UV-vis spectroscopy enhanced the study of the energy band gaps which showed a drastic shifting. The study performed on the surface morphologies of the CdSe thin films exhibited a double layer of deposition; but did not show considerable difference from each other for different temperatures. The EDS pattern helped in determining the stoichiometric ratio.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Influence of Cr Doping On Structural, Morphological and Optical Properties of...IOSR Journals
Cr-doped tin oxide thin films were prepared by spray pyrolysis on glass substrates. X-ray diffraction analysis showed the films were polycrystalline with a tetragonal rutile structure. Increasing the Cr dopant concentration from 10% to 20% caused a shift of diffraction peaks to higher angles, decreasing the interplanar spacing and crystallite size. Scanning electron microscopy images showed the films had a homogeneous, crack-free morphology with spherical grains that decreased in size as the Cr concentration increased. Optical analysis found the energy bandgap increased with higher Cr doping levels, exhibiting a blue shift. The structural, morphological, and optical properties of the films were influenced by the Cr dopant concentration.
The document describes a study on the effect of annealing on the optical properties of cadmium sulfide (CdS) thin films deposited using chemical bath deposition. CdS thin films were deposited on glass substrates at optimized deposition parameters. The as-deposited films and films annealed at temperatures from 100-400°C were characterized using UV-visible spectroscopy. Annealing was found to cause a blue shift in the absorption edge and increase the optical band gap and transmittance of the films. The highest band gap of 3.8 eV and transmittance of 64% were observed for the film annealed at 400°C. Annealing improves the optical properties of CdS thin films by modifying the structural properties of the
This document summarizes a final year project on depositing CdSe nanoparticles multilayers using chemical bath deposition. It introduces CdSe and its properties, the chemical bath deposition technique, and how it was used to deposit different sized CdSe nanoparticles by varying the concentration of the complexing agent NTA. Characterization of the deposited nanoparticles found smaller sizes were produced with higher NTA concentrations. Attempts to deposit two CdSe layers of different sizes on a substrate did not improve solar cell efficiency compared to a single layer. Further work is recommended to address Ostwald ripening in the deposition solution.
Synthesis and Study of Structural, Optical Properties of CoxZn1-xS Semiconduc...IOSR Journals
CoxZn1-xS (x=0-0.1) polycrystalline semiconductor compounds were synthesised by co-precipitation method and were characterised by X-ray diffraction (XRD), UV-absorption, EDAX, SEM and Fourier Transform Infrared (FTIR) studies. XRD studies have shown that these powders have polycrystalline nature with a gradual variation from hexagonal to cubic structure while x changing from 0 to 0.1. UV-abosrption studies revealed that the band gap of CoxZn1-xS (x=0-0.1) samples decreased with increase in cobalt concentration, owing to the enhancement of sp-d exchange interactions and typical d-d transitions. Chemical homogeneity and surface morphology studies were carried out by using EDAX and SEM. Fourier Transform Infrared (FTIR) spectroscopy also revealed that cobalt is induced into the lattice replacing Zinc
Analysis Of Carbon Nanotubes And Quantum Dots In A Photovoltaic Device Slide ...M. Faisal Halim
Francis' presentation to Louis Stokes Association for Minority Participation. Since I co-authored this work I think I have the right to a copy. I was the graduate student Francis was working with.
Comparative Analysis of Optical Properties of Cdo Annealed thin Film deposite...AI Publications
Cadmium oxide transparent thin film is deposited by spray pyrolysis technique on glass subtract at 4000C and annealed at a temperature of 100 °C for one hour. The band gap was found depend on varius parameters is studied. It is noted that the shift in band gap i.e. decrease with the increasing film thickness in the range 2.15 eV to 2.40 eV. The optical constants such as, band gap, refractive index, extinction coefficient as a function of photon energy for all prepared films were calculated. also studied The XRD revealed of thin film of CdO shows polycrystalline in nature
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
This document summarizes a lecture on thin film deposition techniques given by Dr. Toru Hara. It begins with definitions of thin films and their applications in electronic devices, optical coatings, optoelectronic devices, and quantum devices. It then provides brief introductions to specific applications like transistors, oxygen sensors, and LEDs. The main deposition techniques are also summarized, including chemical methods like plating, CSD, CVD, and ALD, as well as physical methods like thermal evaporation, sputtering, PLD, and MBE. Examples of equipment schematics are provided for many of the techniques.
The document provides an overview of a lecture on thin film deposition techniques given by Dr. Toru Hara. It discusses four main applications of thin films: 1) electronic semiconductor devices using band engineering, 2) optical coatings using refractive index engineering, 3) optoelectronic devices using both band and refractive index engineering, and 4) quantum devices using quantum dynamics design. It also describes common thin film deposition methods including chemical solution deposition, chemical vapor deposition, plating, and physical vapor deposition techniques and gives examples of their use in applications such as transistors, optical coatings, LEDs, and superlattices.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Synthesis and application of natural dye sensitizd cds thin films as photoano...eSAT Journals
Abstract
Natural dyes obtained from plants, vegetables and fruits are widely studied and tested as low cost sensitizer for dye sensitized solar cell ( DSSC) in order to replace the rare and expensive inorganic and organic sensitizers. Although, many works have been done using TiO2, ZrO2, ZnO etc. as the nanoporous semiconductor, little importance was given to the use of CdS thin film as a cost effective alternative. In the present study CdS thin films were synthesized by chemical bath deposition (CBD) technique and its optical, structural and morphological properties were investigated by XRD, SEM and UV-Vis absorption spectroscopy. The as synthesized films were found to be nanoporous in nature and are favorable for adsorbing the dyes on to its surface. Two natural dyes extracted from locally available plant leaves namely lawsonia inermis linn and caesalpinia pulcherrima were then adsorbed on the as synthesized CdS thin films for the formation of the working electrode for application in DSSC. The interaction between the nanoporous CdS thin films and the natural dyes were investigated through UV-Vis absorption spectroscopy with an aim to fabricate working electrode for application in DSSC.
Keywords: DSSC, thin film, CdS, natural dyes
Influence of concentration on the structural, optical and electrical properti...iosrjce
IOSR Journal of Applied Physics (IOSR-JAP) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Abnormalities of hormones and inflammatory cytokines in women affected with p...Alexander Decker
Women with polycystic ovary syndrome (PCOS) have elevated levels of hormones like luteinizing hormone and testosterone, as well as higher levels of insulin and insulin resistance compared to healthy women. They also have increased levels of inflammatory markers like C-reactive protein, interleukin-6, and leptin. This study found these abnormalities in the hormones and inflammatory cytokines of women with PCOS ages 23-40, indicating that hormone imbalances associated with insulin resistance and elevated inflammatory markers may worsen infertility in women with PCOS.
A usability evaluation framework for b2 c e commerce websitesAlexander Decker
This document presents a framework for evaluating the usability of B2C e-commerce websites. It involves user testing methods like usability testing and interviews to identify usability problems in areas like navigation, design, purchasing processes, and customer service. The framework specifies goals for the evaluation, determines which website aspects to evaluate, and identifies target users. It then describes collecting data through user testing and analyzing the results to identify usability problems and suggest improvements.
A universal model for managing the marketing executives in nigerian banksAlexander Decker
This document discusses a study that aimed to synthesize motivation theories into a universal model for managing marketing executives in Nigerian banks. The study was guided by Maslow and McGregor's theories. A sample of 303 marketing executives was used. The results showed that managers will be most effective at motivating marketing executives if they consider individual needs and create challenging but attainable goals. The emerged model suggests managers should provide job satisfaction by tailoring assignments to abilities and monitoring performance with feedback. This addresses confusion faced by Nigerian bank managers in determining effective motivation strategies.
A unique common fixed point theorems in generalized dAlexander Decker
This document presents definitions and properties related to generalized D*-metric spaces and establishes some common fixed point theorems for contractive type mappings in these spaces. It begins by introducing D*-metric spaces and generalized D*-metric spaces, defines concepts like convergence and Cauchy sequences. It presents lemmas showing the uniqueness of limits in these spaces and the equivalence of different definitions of convergence. The goal of the paper is then stated as obtaining a unique common fixed point theorem for generalized D*-metric spaces.
A trends of salmonella and antibiotic resistanceAlexander Decker
This document provides a review of trends in Salmonella and antibiotic resistance. It begins with an introduction to Salmonella as a facultative anaerobe that causes nontyphoidal salmonellosis. The emergence of antimicrobial-resistant Salmonella is then discussed. The document proceeds to cover the historical perspective and classification of Salmonella, definitions of antimicrobials and antibiotic resistance, and mechanisms of antibiotic resistance in Salmonella including modification or destruction of antimicrobial agents, efflux pumps, modification of antibiotic targets, and decreased membrane permeability. Specific resistance mechanisms are discussed for several classes of antimicrobials.
A transformational generative approach towards understanding al-istifhamAlexander Decker
This document discusses a transformational-generative approach to understanding Al-Istifham, which refers to interrogative sentences in Arabic. It begins with an introduction to the origin and development of Arabic grammar. The paper then explains the theoretical framework of transformational-generative grammar that is used. Basic linguistic concepts and terms related to Arabic grammar are defined. The document analyzes how interrogative sentences in Arabic can be derived and transformed via tools from transformational-generative grammar, categorizing Al-Istifham into linguistic and literary questions.
A time series analysis of the determinants of savings in namibiaAlexander Decker
This document summarizes a study on the determinants of savings in Namibia from 1991 to 2012. It reviews previous literature on savings determinants in developing countries. The study uses time series analysis including unit root tests, cointegration, and error correction models to analyze the relationship between savings and variables like income, inflation, population growth, deposit rates, and financial deepening in Namibia. The results found inflation and income have a positive impact on savings, while population growth negatively impacts savings. Deposit rates and financial deepening were found to have no significant impact. The study reinforces previous work and emphasizes the importance of improving income levels to achieve higher savings rates in Namibia.
A therapy for physical and mental fitness of school childrenAlexander Decker
This document summarizes a study on the importance of exercise in maintaining physical and mental fitness for school children. It discusses how physical and mental fitness are developed through participation in regular physical exercises and cannot be achieved solely through classroom learning. The document outlines different types and components of fitness and argues that developing fitness should be a key objective of education systems. It recommends that schools ensure pupils engage in graded physical activities and exercises to support their overall development.
A theory of efficiency for managing the marketing executives in nigerian banksAlexander Decker
This document summarizes a study examining efficiency in managing marketing executives in Nigerian banks. The study was examined through the lenses of Kaizen theory (continuous improvement) and efficiency theory. A survey of 303 marketing executives from Nigerian banks found that management plays a key role in identifying and implementing efficiency improvements. The document recommends adopting a "3H grand strategy" to improve the heads, hearts, and hands of management and marketing executives by enhancing their knowledge, attitudes, and tools.
This document discusses evaluating the link budget for effective 900MHz GSM communication. It describes the basic parameters needed for a high-level link budget calculation, including transmitter power, antenna gains, path loss, and propagation models. Common propagation models for 900MHz that are described include Okumura model for urban areas and Hata model for urban, suburban, and open areas. Rain attenuation is also incorporated using the updated ITU model to improve communication during rainfall.
A synthetic review of contraceptive supplies in punjabAlexander Decker
This document discusses contraceptive use in Punjab, Pakistan. It begins by providing background on the benefits of family planning and contraceptive use for maternal and child health. It then analyzes contraceptive commodity data from Punjab, finding that use is still low despite efforts to improve access. The document concludes by emphasizing the need for strategies to bridge gaps and meet the unmet need for effective and affordable contraceptive methods and supplies in Punjab in order to improve health outcomes.
A synthesis of taylor’s and fayol’s management approaches for managing market...Alexander Decker
1) The document discusses synthesizing Taylor's scientific management approach and Fayol's process management approach to identify an effective way to manage marketing executives in Nigerian banks.
2) It reviews Taylor's emphasis on efficiency and breaking tasks into small parts, and Fayol's focus on developing general management principles.
3) The study administered a survey to 303 marketing executives in Nigerian banks to test if combining elements of Taylor and Fayol's approaches would help manage their performance through clear roles, accountability, and motivation. Statistical analysis supported combining the two approaches.
A survey paper on sequence pattern mining with incrementalAlexander Decker
This document summarizes four algorithms for sequential pattern mining: GSP, ISM, FreeSpan, and PrefixSpan. GSP is an Apriori-based algorithm that incorporates time constraints. ISM extends SPADE to incrementally update patterns after database changes. FreeSpan uses frequent items to recursively project databases and grow subsequences. PrefixSpan also uses projection but claims to not require candidate generation. It recursively projects databases based on short prefix patterns. The document concludes by stating the goal was to find an efficient scheme for extracting sequential patterns from transactional datasets.
A survey on live virtual machine migrations and its techniquesAlexander Decker
This document summarizes several techniques for live virtual machine migration in cloud computing. It discusses works that have proposed affinity-aware migration models to improve resource utilization, energy efficient migration approaches using storage migration and live VM migration, and a dynamic consolidation technique using migration control to avoid unnecessary migrations. The document also summarizes works that have designed methods to minimize migration downtime and network traffic, proposed a resource reservation framework for efficient migration of multiple VMs, and addressed real-time issues in live migration. Finally, it provides a table summarizing the techniques, tools used, and potential future work or gaps identified for each discussed work.
A survey on data mining and analysis in hadoop and mongo dbAlexander Decker
This document discusses data mining of big data using Hadoop and MongoDB. It provides an overview of Hadoop and MongoDB and their uses in big data analysis. Specifically, it proposes using Hadoop for distributed processing and MongoDB for data storage and input. The document reviews several related works that discuss big data analysis using these tools, as well as their capabilities for scalable data storage and mining. It aims to improve computational time and fault tolerance for big data analysis by mining data stored in Hadoop using MongoDB and MapReduce.
1. The document discusses several challenges for integrating media with cloud computing including media content convergence, scalability and expandability, finding appropriate applications, and reliability.
2. Media content convergence challenges include dealing with the heterogeneity of media types, services, networks, devices, and quality of service requirements as well as integrating technologies used by media providers and consumers.
3. Scalability and expandability challenges involve adapting to the increasing volume of media content and being able to support new media formats and outlets over time.
This document surveys trust architectures that leverage provenance in wireless sensor networks. It begins with background on provenance, which refers to the documented history or derivation of data. Provenance can be used to assess trust by providing metadata about how data was processed. The document then discusses challenges for using provenance to establish trust in wireless sensor networks, which have constraints on energy and computation. Finally, it provides background on trust, which is the subjective probability that a node will behave dependably. Trust architectures need to be lightweight to account for the constraints of wireless sensor networks.
This document discusses private equity investments in Kenya. It provides background on private equity and discusses trends in various regions. The objectives of the study discussed are to establish the extent of private equity adoption in Kenya, identify common forms of private equity utilized, and determine typical exit strategies. Private equity can involve venture capital, leveraged buyouts, or mezzanine financing. Exits allow recycling of capital into new opportunities. The document provides context on private equity globally and in developing markets like Africa to frame the goals of the study.
This document discusses a study that analyzes the financial health of the Indian logistics industry from 2005-2012 using Altman's Z-score model. The study finds that the average Z-score for selected logistics firms was in the healthy to very healthy range during the study period. The average Z-score increased from 2006 to 2010 when the Indian economy was hit by the global recession, indicating the overall performance of the Indian logistics industry was good. The document reviews previous literature on measuring financial performance and distress using ratios and Z-scores, and outlines the objectives and methodology used in the current study.
Unlocking Productivity: Leveraging the Potential of Copilot in Microsoft 365, a presentation by Christoforos Vlachos, Senior Solutions Manager – Modern Workplace, Uni Systems
UiPath Test Automation using UiPath Test Suite series, part 6DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 6. In this session, we will cover Test Automation with generative AI and Open AI.
UiPath Test Automation with generative AI and Open AI webinar offers an in-depth exploration of leveraging cutting-edge technologies for test automation within the UiPath platform. Attendees will delve into the integration of generative AI, a test automation solution, with Open AI advanced natural language processing capabilities.
Throughout the session, participants will discover how this synergy empowers testers to automate repetitive tasks, enhance testing accuracy, and expedite the software testing life cycle. Topics covered include the seamless integration process, practical use cases, and the benefits of harnessing AI-driven automation for UiPath testing initiatives. By attending this webinar, testers, and automation professionals can gain valuable insights into harnessing the power of AI to optimize their test automation workflows within the UiPath ecosystem, ultimately driving efficiency and quality in software development processes.
What will you get from this session?
1. Insights into integrating generative AI.
2. Understanding how this integration enhances test automation within the UiPath platform
3. Practical demonstrations
4. Exploration of real-world use cases illustrating the benefits of AI-driven test automation for UiPath
Topics covered:
What is generative AI
Test Automation with generative AI and Open AI.
UiPath integration with generative AI
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Threats to mobile devices are more prevalent and increasing in scope and complexity. Users of mobile devices desire to take full advantage of the features
available on those devices, but many of the features provide convenience and capability but sacrifice security. This best practices guide outlines steps the users can take to better protect personal devices and information.
HCL Notes und Domino Lizenzkostenreduzierung in der Welt von DLAUpanagenda
Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-und-domino-lizenzkostenreduzierung-in-der-welt-von-dlau/
DLAU und die Lizenzen nach dem CCB- und CCX-Modell sind für viele in der HCL-Community seit letztem Jahr ein heißes Thema. Als Notes- oder Domino-Kunde haben Sie vielleicht mit unerwartet hohen Benutzerzahlen und Lizenzgebühren zu kämpfen. Sie fragen sich vielleicht, wie diese neue Art der Lizenzierung funktioniert und welchen Nutzen sie Ihnen bringt. Vor allem wollen Sie sicherlich Ihr Budget einhalten und Kosten sparen, wo immer möglich. Das verstehen wir und wir möchten Ihnen dabei helfen!
Wir erklären Ihnen, wie Sie häufige Konfigurationsprobleme lösen können, die dazu führen können, dass mehr Benutzer gezählt werden als nötig, und wie Sie überflüssige oder ungenutzte Konten identifizieren und entfernen können, um Geld zu sparen. Es gibt auch einige Ansätze, die zu unnötigen Ausgaben führen können, z. B. wenn ein Personendokument anstelle eines Mail-Ins für geteilte Mailboxen verwendet wird. Wir zeigen Ihnen solche Fälle und deren Lösungen. Und natürlich erklären wir Ihnen das neue Lizenzmodell.
Nehmen Sie an diesem Webinar teil, bei dem HCL-Ambassador Marc Thomas und Gastredner Franz Walder Ihnen diese neue Welt näherbringen. Es vermittelt Ihnen die Tools und das Know-how, um den Überblick zu bewahren. Sie werden in der Lage sein, Ihre Kosten durch eine optimierte Domino-Konfiguration zu reduzieren und auch in Zukunft gering zu halten.
Diese Themen werden behandelt
- Reduzierung der Lizenzkosten durch Auffinden und Beheben von Fehlkonfigurationen und überflüssigen Konten
- Wie funktionieren CCB- und CCX-Lizenzen wirklich?
- Verstehen des DLAU-Tools und wie man es am besten nutzt
- Tipps für häufige Problembereiche, wie z. B. Team-Postfächer, Funktions-/Testbenutzer usw.
- Praxisbeispiele und Best Practices zum sofortigen Umsetzen
Unlock the Future of Search with MongoDB Atlas_ Vector Search Unleashed.pdfMalak Abu Hammad
Discover how MongoDB Atlas and vector search technology can revolutionize your application's search capabilities. This comprehensive presentation covers:
* What is Vector Search?
* Importance and benefits of vector search
* Practical use cases across various industries
* Step-by-step implementation guide
* Live demos with code snippets
* Enhancing LLM capabilities with vector search
* Best practices and optimization strategies
Perfect for developers, AI enthusiasts, and tech leaders. Learn how to leverage MongoDB Atlas to deliver highly relevant, context-aware search results, transforming your data retrieval process. Stay ahead in tech innovation and maximize the potential of your applications.
#MongoDB #VectorSearch #AI #SemanticSearch #TechInnovation #DataScience #LLM #MachineLearning #SearchTechnology
Best 20 SEO Techniques To Improve Website Visibility In SERPPixlogix Infotech
Boost your website's visibility with proven SEO techniques! Our latest blog dives into essential strategies to enhance your online presence, increase traffic, and rank higher on search engines. From keyword optimization to quality content creation, learn how to make your site stand out in the crowded digital landscape. Discover actionable tips and expert insights to elevate your SEO game.
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UiPath Test Automation using UiPath Test Suite series, part 5
11.m. kamruzzaman 117 124
1. Innovative Systems Design and Engineering www.iiste.org
ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online)
Vol 2, No 5, 2011
Elemental, structural and optical properties of Cd1-xCoxS thin
films prepared by spray pyrolysis technique
M. Kamruzzaman
Department of Physics, Begum Rokeya University, Rangpur -5400, Bangladesh.
Corresponding author and e-mail: mkzaman_phybuet@yahoo.com
T. R. Luna
Department of Physics, Bangladesh University of Engineering and Technology (BUET), Dhaka-1000, Bangladesh.
E-mail: tamjidarahman@gmail.com
J. Podder
Department of Physics, Bangladesh University of Engineering and Technology (BUET), Dhaka-1000, Bangladesh.
E-mail: jpodder@phy.buet.ac.bd
The research is financed by Bangladesh University of Engineering and Technology (BUET),.Dhaka-1000,
Bangladesh.
Abstract
The Cd1-xCoxS (x=0.00, 0.10, 0.20 and 0.40) thin films were deposited onto glass substrate at temperature
523K by using a low cost spray pyrolysis deposition (SPD) technique. The deposited films have been
characterized their elemental, structural and optical properties measurements by energy dispersive X-ray,
X-ray diffraction and UV-VIS spectrophotometer. Energy dispersive X-ray (EDX) analysis confirmed the
presence of Cd, S and Co compositions in the films with appropriate stoichiometric. The as deposited films
were amorphous in nature. The optical band gap of the films was decreased from 2.54 eV to 2.40 eV.
Refractive index and the refractive index were affected by the doping concentration.
Keywords: SEM, spray pyrolysis, band gap and solar cell
1. Introduction
Cadmium sulfide (CdS) is a transparent metal sulfide semiconductor of the II-VI group compound
semiconductors. Feitosa et al. (2004) reported that CdS has intensive attention due to their very important
role on the photovoltaic technology, optoelectronic devices and solar cell fabrication. Archbold et al. (2005)
examined that CdS is a hexagonal closed packed structure and has a wide band gap of 2.53eV, low resistivity
and high transparency in the visible range and high light trapping characteristics. Several authors have been
doped CdS with a wide variety of (F, Pt, Pb, Zn, Al, Co, In, Sn, etc.) elements to meet the demands of several
application fields such as thin film solar cells ( Ristova and Ristov 1998), electrochemical cells (Jadhav et al.
2001), gas sensor (Kanemitsu et al. 2002) and it also has been employed in high efficiency solar cells
formed with Cu2S (Hall et al. 1979 ), Cu (InGa) Se2 (Nakoda et al. 1994), etc. Wu et al. (2006) proposed that
CdS doped with transition metal ions (Fe, Ni, Mn ,Co and Cr), so-called dilute magnetic semiconductors
(DMSs), such semiconductors offer the great opportunity to integrate the magnetic, electrical and optical
advantages into a single semiconductor material, which provides many potential applications in the field of
semiconductor spintronic and optoelectronic devices. Now a day’s most of the semiconductors research is
dedicated towards the fabrication of small-sized particle that includes the growth of semiconductor
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Vol 2, No 5, 2011
nanocrystalline materials. These materials show a large optical band gap when the crystallite size becomes
less than the Bohr exciton radius which is experimentally proved by Murray et al. (1995) & Mathur et al.
(2004). Zenrui et al. (2002) found that CoS is an intrinsic semiconductor and a suitable candidate for
photovoltaic or photothermal applications which has an optical band gap of 1.15 eV with cubic structure.
Thus the alloying of Co with CdS may tune the optical band gap which may provide the suitability of this
material for solar cells, optical window layers of photovoltaic cells, photodetectors, photoresistors etc
applications.
In thin film preparation a variety of deposition techniques have been used to grow CdS and Co doped CdS
thin films such as, chemical bath deposition (Zenrui, Yu et al. 2002 & Ezema et al. 2006), surfactant-assisted
method (Sathyamoorthy et al. 2010), implantation-assisted method (Chandramohan et al. 2009), modified
Bridgeman method (Lewicki et al. 1991), spray pyrolysis technique (Bacaksiz et al. 2008) etc. Spray
pyrolysis deposition technique have also been considered as a viable technique for production of Co doped
CdS thin films due to its many advantages over the conventional methods, viz., low cost experimental set up,
high spatial selectivity, precise control over maneuvering the impurity concentration and possibility to
overcome the solubility limit. In addition, this technique could be used for the production of large scale area
for thin film deposition without employing any high vacuum system (Bedir et al. 2002).
In this work, Cd1-xCoxS thin films have been synthesized and investigated elemental, structural and optical
properties by using EDX, XRD and UV-VIS spectroscopy.
2. Experimental
2.1 Preparation procedure
Figure 1 is a typical experimental setup for the preparation of Cd1-xCoxS thin films by the spray pyrolysis
method. Aqueous solution of 0.1M cadmium acetate Cd (CH3COO)2.3H2O, 0.2M thiourea (NH2CSNH2) and
0.1M cobalt acetate Co(CH3COO)2.4H2O were taken as sources of Cd, S and Co. A considerable amount of
(100 ml) solution was taken in the Beaker ‘F’ fitted with the spray nozzle ‘A’. The clean substrate with a
suitable mask was put on the susceptor of the heater ‘H’. The distance between the tip of the nozzle and the
surface of the glass substrate was kept 25 cm. The substrate temperature was kept at 523 K and was measured
by placing a copper constantan thermocouple on the substrate. When compressed air is passed through ‘P’ (at
0.50 bar pressure) and at the same time water based precursor solution is feed at the nozzle A, then the
solution sprayed and was automatically carried to the reactor zone upto 5 minutes where film was deposited
onto the heated substrate.
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Vol 2, No 5, 2011
Figure 1. Experimental set up of spray pyrolysis method.
In the hot-zone, the atomized solution is dried and the constituent metal salts decompose and form intimate
Cd1-xCoxS films. The possible chemical reaction may take place on the heated substrate as follows:
523K
Cd 1 x (CH 3 COO) 3 3H 2 O Co x (CH 3 COO) 2 4 H 2 O NH 2 CSNH 2 Cd 1 x Co x S
Decompose
NH 3 NH 4 7CO2 4CH 4 2 H 2 3Steam
2.2 Characterization
The thicknesses of the films were measured by the setup of Fizeau fringes method at the department of
Physics, BUET. Energy dispersive X- rays (EDX) were taken by the scanning electron microscopy (SEM)
setup (Inspect IS50 FEI Company). The X-ray diffraction (XRD) of as deposited films were taken by using a
molybdenum CuK ( = 1.54178 Å), radiation diffractometer, PHILIPS model “X’Pert PRO XRD System.
The optical absorbance and transmittance spectra of the as-deposited films with respect to plain glass
substrate were taken at room temperature using double beam UV-VIS spectrophotometer (UV-1601PC
Shimadzu, Japan) in BCSIR, for wavelength 300 nm to1100 nm.
3. Results and discussion
3.1 Compositional Studies
The quantitative analysis of the films is shown in figure 2(a-c) and table1 respectively.
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Figure 2. EDX spectra of Cd1-xCoxS thin films for (a) x = 0.40, (b) x = 0.20 and (c) x = 0.40.
Some peaks are observed in figure 2 (a) that corresponds to Cd and S and confirms the CdS thin film. For
x=0.20 and 0.40 there have some extra peaks of Co in the spectra. It is worth to mention that the as-deposited
Cd1-xCoxS films are stoichiometric. A silicon (Si) and an oxygen (O) strong peaks are also observed due to
glass substrate. The decreasing of Cd peak height with increasing Co indicates the incorporation of Co. From
table 1 it is evident that for all the films the amounts of Cd, S and Co are present in an excellent ratio.
Table 1. Atomic % for different compositions of Cd1-xCoxS thin films.
Compositions Co atomic% Cd atomic% S atomic%
CdS 00 55.17 44.83
Cd0.80Co0.20S 12.59 37.35 50.06
Cd0.60Co0.40S 19.89 34.04 46.07
3.2 X-Ray Diffraction (XRD)
The X-ray diffraction patterns of pure CdS and Co doped CdS of as-deposited films as shown in fig. 3.
Figure 3 shows that all the films contain a broad peak indicated the amorphous nature.
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Figure 3. XRD spectra of as-deposited Cd1-xCoxS thin films.
3.3 Optical band gap
The absorbance and transmittance spectra of as-deposited films are shown in Figures 4(a) and 4(b). These
spectra reveal that the films grown under the same parametric conditions have low absorbance in the visible
and near infrared regions and are high in the ultraviolet region. However, absorption increases with
increasing Co. Transmittance of all the films demonstrate more than 65% above wavelengths 550 nm and
from 550 nm to 450 nm there is a sharp fall in the %T of the films, which is due to the strong absorbance of
the films in this region. It has been observed that the over all %T decreases with Co content. This result is
quite similar to that of the reported results of (Mathur et al. 2004 & Zenrui, Yu et al. 2002) film deposited
by chemical bath deposition technique. The direct band gap energy of the films were determined from the
(αhν)2 vs. hν curve (figure 5). Band gap (Eg) of the films decreases from 2.54 eV to 2.40 eV, which indicated
that small amount incorporation of Co affects on the optical band gap. This reduction of the band gap is
explained (Bacaksiz et al. 2008; Mishack et al. 2010 & Koidl 1977) by sp–d exchange interactions between
the host material s-p band electrons and the localized d electrons of the Co ions.
(a)
(b)
Figure 4. (a) Variation of absorbance and (b) transmittance as a function of wavelength of Cd1-xCoxS films.
This variation of the band gap energy may be useful to design a suitable window material in fabrication for
solar cells.
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Figure 5. Plots of (αhν) 2 vs. photon energy (hν) for as-deposited Cd1-xCoxS thin films.
3.4. Extinction Coefficient
The extinction coefficient, (k) obtained from the relations (1) and (2)
k (1)
4
A
and 2.303 (2)
d
where, λ is the wavelength and α is the absorption coefficient, A is the optical absorbance and d is the
thickness of the film. It is observed from figure 6 that the extinction coefficient falling with increasing
wavelength from 300 to 500 nm. This may be due to the absorption of light at the grain boundaries. After
wavelength 500 nm the value of ‘k’ remains constant.
Figure 6. Variation of extinction coefficient as a function of wavelength for Co 1-xCdxS films.
3.5. Refractive Index
The refractive index, (n) of the films were determined using the relation (3)
1 R 4R
n
1 R 2 k
2
(3)
1 R
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where, k is the extinction coefficient and R is the optical reflectance. The refractive index increases sharply in
the wavelength between 300 to 480 nm which means it loses its energy, due to various loss mechanisms such
as the generation of phonons, photo generation, free carrier absorption, scattering, etc.
Figure 7. Variation of refractive index as a function of wavelength of the Cd1-xCoxS thin films.
The values of n decreases from 500 nm to 560 nm after that the value of ‘n’ remains more or less constant as
shown in figure 7. The refractive index of the as-deposited films increases slowly with Co. So it is
attributed to the variety of different impurities and defects.
4. Conclusions
The amounts of Cd, S and Co are present in all the films with an excellent ratio. The as deposited films are
amorphousness. The direct band gap energy of the films decreases from 2.54 eV to 2.40 eV. Extinction
coefficient and refractive index tend to increase with increasing doping concentration. These optical values
are appropriate for designing optical devices such as solar cells, optical window layers of photovoltaic cells,
photo detectors etc.
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