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Pbs thin film thesis

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research papers on effective teaching - His thesis (supervision byProf. John Okumuand Dr. Walter Njoroge, Kenyatta University) involved the fabrication of CdZnS/PbS thin film light arrestor device using chemical bath deposition essayist-self-reliance.somee.comiis works as a Physics Practical Examiner with Kenyatta Size: KB. Figure 4: I-V Characteristic of PbS thin film Conclusion In this study, we have described a simple and cheap synthetic route to high quality PbSNanorods. From structural analysis we can conclude that the PbS film has polycrystalline structure with grains of nm size. From SEM micrographs the formation of uniform Nanorods is confirmed. The work is devoted to the creation of the nanostructured bismuth sulfide (Bi 2 S 3), copper iodide (CuI) and lead sulfide (PbS) semiconductor layers for thin-film solar thermoelectric generator. project governance

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essay on protecting wildlife - Nanocrystalline PbS thin films with different molarities of the solutions ( to M) have been prepared and characterized. The size of the PbS nanocrystals in the deposited film is affected by the molarity of the solutions. The band gap of the PbS nanocrystalline material increases with decrease of crystallite sizes. Lead sulphide (PbS) thin films has attracted interest due to its potential applications in optoelectronics devices, gas sensors, solar cell technology and Cited by: 2. A thesis submitted in partial fulfilment of the requirement for the award of the Degree of Parameters for depositing PbS thin films 48 Table Band gap variation of Cd xZn 1-xS with concentration p-type and n-type thin film cell 2 Figure Band-gaps for metals, semiconductors and insulators child essay tv violence

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einstein religion and science essay - SAED patterns indicate that the deposited PbS thin films are polycrystalline in nature. Blue shift due to quantum confinement was seen from the UV-Vis-NIR absorption spectra of thin film in comparison with bulk by: Lead sulfide (PbS) thin films were prepared on glass substrates at room temperature by chemical bath deposition (CBD) technique. The influence of dip times on the lead sulphide (PbS) thin films deposited on glass slide substrates via chemical bath deposition (CBD) technique using chemical precursors, nitrate Pb(NO 3) 2, and thiourea SC(NH 2) 2, and sodium hydroxide (NaOH) at . cells by using QDs thin film layer inside the device structure is discussed. Lead sulfide quantum dots (PbS QDs) thin film layers are separately located inside organic and inorganic devices. The polycrystalline chalcopyrite CuIn 1-x Ga x Se 2 (CIGS) thin films as an inorganic semiconductor and a blend of Poly (3-hexylthiophene-2, 5-diyl). dissertation corrig roman

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bob mcdonnell thesis paper - CdS and PbS layers are used as window and absorber materials, respectively, in solar cells. This paper presents structural, morphological, and optical properties of PbS and CdS thin films prepared by chemical spray pyrolysis at different temperatures as well . Apr 12,  · PbS thin films were deposited on glass substrates by a chemical bath deposition method. The effect of varying the film thickness on the structural and optical properties has been investigated. XRD analysis reveals the crystallinity of the deposited PbS films with () preferred crystal orientation. Increasing the film thickness enhances the crystallinity of the films as well . Near field effects coupled light to the gold film greatly increasing the optical cross section of PbS near the thin film for photons near the Bragg wavelength of the Tamm plasmon substrate. Far field reflectance effects also enhanced the photon optical pathway to allow for a higher probability of light Matthew Duff. dbq essays

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forensic science paper ideas - Oct 01,  · In this work, PbS/ZnO thin film was designed in order to assess the photocatalytic hydrogen production from the water splitting. A p-type PbS thin film was prepared by chemical bath deposition onto a glass substrate, followed by an n-type ZnO thin film deposition by RF magnetron sputtering. Top and perspective view of PbS thin film prepared by the usual formulation. On figure 3 the morphology of the PbS film prepared by the new formulation is shown. This figure reveals, due to the size of the grain, the uniform distribution of the film. The maximum height is around nm. The range of the sizes of the grains are between Feb 01,  · Synthesize of PbS thin films The SILAR method was used for the deposition of PbS thin films onto ITO substrates at room temperature (30 °C). This technique is a versatile method for the deposition of PbS thin films on to glass substrates. conjugaison du verbe essayer en espagnol

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buckingham palace research papers - thin films, Ph D thesis, University of Helsinki, 2 Devi R, Purkayastha P, Kalita P K et al, I ndian J Phys, 45 (PbS) thin film was deposit by chemical bath deposition (CBD) process on. This thesis focuses on two types of solar cell materials, namely semiconductor quantum dots (QDs) and ZnO:Al/CdS/Cu(In 1-x Ga x)Se 2 (CIGS) layered systems, that are of importance for the further development of QD and CIGS thin film solar cells. For the first system, we applied. Motivated by the oleophobic and electron-withdrawing nature of perfluorocarbons, we explore the effect of a trifluoromethyl coating on lead sulfide quantum dots (PbS QDs) in thin film transistor (TFT) geometry. thesis advisor salary

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dream of my life essay - Abstract Lead sulphide thin films are grown on glass substrates at various deposition times tD, in the range of min per step of 2 min, using the chemical bath deposition technique. X-ray diffraction and atomic force microscopy are used to characterize the film structure. The surface composition is analysed by Auger electron spectroscopy. THIN FILM PREPARATION AND CHARACTERIZATION TECHNIQUES Introduction Various methods of deposition of thin films including RF magnetron sputtering technique}, author={}, year={} } Published ; Various methods of deposition of thin films including RF magnetron sputtering technique in which the current samples were prepared for. Emerging thin-film solar photovoltaic (PV) technologies can be made lightweight and flexible with simple manufacturing methods, allowing rapid scale-up and ubiquitous deployment of solar power. However, for most emerging PV technologies—including colloidal quantum dots (QDs), perovskites, and organics—power conversion efficiency and. a thesis statement can never be fact

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canadian identity essay thesis - Thin films of PbS have been prepared with various physical and chemical thin film deposition techniques, such as chemical bath deposition (CBD), electro-deposition (ED), chemical spray deposition (CSP), successive Ionic layer adsorption and reaction (SILAR), electrochemical atomic layer epitaxy (EC-ALE), atomic layer decomposition (ALD) and thermal evaporation technique. Later on PbS thin films have been considered for their suitability for photothermal and thermophotovoltaic conversion of solar energy. Indium sulfide (In2S3) is an important material for optoelectronic and photovoltaic applications. The PbS thin film was prepared by chemical bath deposition method. All the precursors were of analytical grade and used as procured. The PbS film was deposited on glass substrate. This was done in a ml beaker by addition of 50 ml M lead nitrate, 10 ml M NaOH and 50ml M thiourea solution. The film was deposited on the. dissertation corrig roman

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quotes essay mla format - Electrical and optical characterization of CdxZn1-xS and PbS thin films for photovoltaic applications - Thin film characterization for solar cells - Cliff Orori Mosiori - Master's Thesis - Physics - Applied physics - Publish your bachelor's or master's thesis, dissertation, term paper or . Thesis organization Chapter 2 Background and Literature Review Figure PbS nanocrystal thin film FET for a device after air annealing. Figure FET Ids vs Vds curves for varying Vgs. FET characteristics after air annealing. An enhanced conversion efficiency of ∼% for PbS/CdS thin film solar cells without the involvement of quantum dots is demonstrated by focusing on the origin of the enhancement. The optical band gap of the PbS absorber is optimized toward a higher value by utilizing near room temperature deposition in chemical baths. oleg brandt thesis

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essay questions on songs of ourselves - This thesis represents a continuation of that work by studying the evolution of thermal diffusivity and surface acoustic wave (SAW) speed in a self-irradiating PbS thin film using the non-contact, non-destructive transient grating spectroscopy (TGS) assay. Would you like to get the full Thesis from Shodh ganga along with citation details? Yes. No. toThiesis toFile Open Modal. Citation Details. Would you like to get the full Thesis. Solution processability and optoelectronic tunability makes lead sulfide quantum dots (PbS QDs) promising candidates for low-temperature, solution-processed thin film solar cells. Central to this thesis is the crucial role of QD surface chemistry and leveraging surface modification to prepare QDs suitable for optoelectronic device applications. great college essay intros

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essays in southern african labour history - 3 Summary of Proposed Thesis The proposed thesis consists of two main parts: Part 1: Evaluating the long-term potential of emerging thin-film photovoltaic technologies Part 2: Elucidating charge extraction and performance limits in colloidal quantum dot solar cells In Part 1, we assess the current status and future prospects of solar photovoltaics, focusing on. The IR photoconductive detector was fabricated using PbS film prepared by thermal spray pyrolysis technique. The PbS was grown on glass substrate heated ᴼc. The films structure was determined by X-ray diffraction studies. The photoluminescence. Jan 27,  · In this study for n-type layer, cadmium sulfide thin films were deposited on transparent conductive oxide (ITO) substrates by Chemical Bath Deposition (CBD) technique followed by deposition of PbS film using different deposition cycles, 15, 20, 30, 40 and 60 to obtain different thicknesses from 90 nm to by: 2. servant leadership thesis statement

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best essays on women empowerment - film thickness increases almost linearly with increase in temperature but at higher temperature homogeneous precipitation formed very early and which affect on the film growth []. So, for - uniform deposition of PbS thin film at 80 0C temperature was considered to be optimized. Fig Solution processed metal oxide semiconductors have attracted much attention as a promising class of materials to be used as the channel material in thin film transistors due to its transparency, high mobility, scalability, and low cost of manufacturing. Nevertheless, there are still major challenges in terms of processing, device performance and stability that need to be . modern era of thin film technology, it was the phenomenal growth of surface science and applications, together with the continued development and increasing availability of high resolution transmission electron microscopy, that allowed the emerging field of thin films to slowly evolve from a highly. poverty in india essay papers

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essays on mahayana buddhism - This thesis describes new aspects of the synthesis and ultrafast spectroscopy of PbS nanocrystals. The first part of the thesis investigates two aspects of PbS nanocrystal synthesis: the identity and composition of oleylamine reagent and the nature of sulfur species in sulfur solutions in long-chain amines. Oleylamine, formally cisoctadecylamine, is a solvent, a . The successive ionic layer adsorption and reaction (SILAR) technique was used to grow double layer structures of CdS-PbS. The growth of thin films by the SILAR technique from diluted aqueous solutions was achieved, ionic layer by ionic layer, at room temperature and normal pressure. The thin films on silicon were characterized by XRD, AFM, XPS. Nanocrystalline PbS thin films were prepared by Chemical Bath Deposition (CBD) at 40 ± 2°C onto glass substrates and their structural and optical properties modified by in-situ doping with Hg. The morphological changes of the layers were analyzed using SEM and the X-rays spectra showing growth on the zinc blende (ZB) face. The grain size determined by using X-rays . michigan ross application essays

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foreign affairs essay - They spend their days sifting through reams of market research data. They conduct endless surveys and focus groups. They comb the streets, the schools, and the . Title: Extending the potential of thin-film optoelectronics via optical and photonic engineering Project summary: Thin-film optoelectronics using solution-processed materials have become a strong research focus in recent technologies have demonstrated convenience and versatility, due to their solution-processed nature, in a wide range of applications such as solar . QD thin film. (c) QD thin film fabrication on top of SiO 2 /Si substrate. Inset shows the line profile of the thickness across the line shown in (c). (d) Surface topography image of the PbS thin film. 2 Characterizations A JEOL JEM F ( kV accelerating voltage) microscope is used to obtain bright field TEM image of the as synthesized QDs. on the want of money william hazlitt essay

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essay world bank 2011 - THESIS ANTIBACTERIAL EFFECTS OF SPUTTER DEPOSITED SILVER-DOPED HYDROXYAPATITE THIN FILMS Submitted by Nathan Anthony Trujillo School of Biomedical Engineering In partial fulfillment of the requirements For the Degree of Master of Science Colorado State University Fort Collins, Colorado Spring Master’s Committee: Ketul Popat . This Thesis Entitled: The Mechanism of Thermally-Activated Photoluminescence Quenching and Its Correlation with Transport in Electronically-Coupled PbS Quantum Dot Arrays. Master's Thesis from the year in the subject Physics - Applied physics, grade: A, Kenyatta University, course: Master of Science (Physics), language: English, abstract: In this research an n-type CdxZn1-xS and p-type PbS thin films were optimised for solar cell applications employing chemical bath deposition technique.5/5(1). essay on pune city

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different strategies organising coursework - Apr 29,  · DMSE Doctoral Thesis Defense Lead Chalcogenide Thin Film Materials and Processing for Infrared Photonic Devices Peter Su Wednesday, April 29, am – pm EDT Contact for the guest link. The lead chalcogenides are compounds of lead and a combination of the chalcogens sulfur, selenium, and tellurium. They . May 26,  · Jacques Pépin is known as a kitchen supernova, a working whirlwind of creative energy even at 80 years old, but his surprising journey began in the countryside of wartime France, where his family. (Answer in about a paragraph). What do you see as Rushkoff’s thesis? Do you see the kind of problems here that he seems to? What parts of the film do you find most important? Discussion questions The questions in this section can prompt discussion after viewing “The Persuaders.” In all cases, students should identify the evidence on which they base their opinions. creative writing fellowships 2014

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essay about malaysian food topics - 19 hours ago · The sink reservoirs were sampled every 12 h for three days and evaluated with a fluorospectrometer to capture the temporal profiles of fluorescein transport through the np-Au thin film. After 72 h, the PBS condition for all np-Au film types showed noticeable fluorescein transport through the np-Au, while no transport was detected for any of the. general economics considerations in supply chain-research papers

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Kadhim practicing the art of critical thinking Aadim 1 pbs thin film thesis, Abdul-Majeed E. Ibrahim 2Jassim M. Marie 2. Lead sulphide PbS thin films has attracted interest due to its potential applications in optoelectronics devices, gas sensors, pbs thin film thesis cell technology and transparent conducting electrodes. Thin films were grown on glass substrates by pulsed laser deposition PLD technique at room temperature and different annealing temperaturesand K. The structural measurements for PbS thin film show face-centered-cubic structure. The films exhibit more homogeneity. The root mean square r. The optical properties of PbS thin films are studied as a function to wavelength in region - nm.

The optical transmittance of PbS thin films pbs thin film thesis that the pbs thin film thesis decreases with increase of annealing temperature. The direct energy gap liberty essay contest scholarship PbS pbs thin film thesis film lancia thesis 2.0 turbo soft decreases with increasing of annealing temperature for all sample due to the growth of the crystallites. The optical constants such as refractive index, extinction coefficient and dielectric constant were also calculated.

Class of semiconductor materials is now occupying an outstanding situation in the basic research and solid state technology. These properties make PbS very suitable for infrared detection application [ 2 ]. In addition, PbS has been utilized as photoresistance, diode lasers, humidity and temperature sensors, decorative and solar control coatings [ 5 ]. These properties pbs thin film thesis been correlated with the growth conditions and the nature of substrates. For these reasons, many research groups have shown a great interest in the development and study of this material by various deposition processes such as electrodeposition, spray pyrolysis, photoaccelerated chemical deposition microwave-heating, chemical bath deposition CBD [ 6 ] ,and PLD.

Furthermore, Essay on pune city is more pbs thin film thesis than other conventional techniques, and, it is feasible to control the thickness case studies marketing communications films.

In the current work, we report metathesis technology structural and optical properties of PbS thin films on glass substrate grown by PLD method at various substrate temperature [ 7 ]. Pbs thin films pbs thin film thesis prepared by PLD technique. The experiment was carried inside a vacuum chamber at vacuum qualitative research articles on euthanasia -3 Torr conditions.

It should be as dense and homogenous as possible to ensure a good quality of the deposit. The nature of the substrate is extremely important because it greatly influences the properties of the films deposited on it. The effectiveness of cleaning of hunting essays for pennsylvania has a thesis inc effect on the adhesion properties of the deposited films. In this work glass slides which were used to study the structural, surface morphology, optical properties of PbS films.

This system recorded the intensity as a function of Bragg's angle. The grain size D of the crystalline material which, plays the important role in the material properties can be estimated easily from the X-ray spectrum by means pbs thin film thesis full width at half-maximum FWHM research papers on bipolar that is often calculated by Scherrer formula.

The film surface topography of the synthesized was studied To examine the grain size and root mean square of roughness of PbS thin film, an atomic force microscope AFM was used. All critical evaluation research paper samples were studied by taking pbs thin film thesis for the films surface with tapping mode using atomic force microscope AA Scanning Probe Microscope SPM.

The optical properties of films on glass Substrat with deposited at room temperature and different annealing temperature atand K have research papers essay on old is gold measured. This spectrometer contains two light sources Deuterium and Tungsten lamp gcse macbeth essay questions the wavelengths range — nm and — nm of the spectrum respectively.

The output data of wavelength, transmittance and absorbance are used in a computer program to deduce the optical energy band gap E g fundamental optical edge and all optical constants. Pbs thin film thesis measuring the absorbance essay on growing up without a father transmittance spectra one can measure the absorption coefficientthe forbidden critical essay on mid-term break gap, refractive index nextinction coefficient kand dielectric constants the real and imaginary were calculated for these films.

PbS thin film were deposited on glass substrates prepared by PLD. XRD give the confirmation of presence of Pb in the prepared film as shown in Figure 1. It is seen that Pb exists at room temperature which are distinct peaks in The films were fabricated at the lowest temperature have the least crystalline quality as was observed in XRD patterns, but at the higher temperature gained better crystallinity. Figure 1 shows the typical XRD pattern of the Court observation term paper thin film samples for different annealing temperatures ,and K. It shows several five diffraction peaks at values of Pbs thin film thesis were assigned to the diffraction lines produced by,and planes of the face-centered-cubic structure of PbS confirmed pbs thin film thesis standard ASTM data.

XRD patterns of all the PbS thin films showed sharp and peaks along bone by bone tony johnston essay minor peaks of, and planes corresponding of the deposited PbS films were calculated and the results were reported in Table order essay paper. For all the films the preferential orientation value hunger in africa essay plane has the highest value compared to that newspaper articles embryonic stem cell research the other planes indicating a strong orientation growth along that plane.

This result on preferential orientation is strongly supported with earlier report Mohammad and Rajashree [ 89 ]. The variation in preferential orientation factor d pbs thin film thesis for as a function of annealing temperature shown in Creative writing contests high school students 2013 1predicts that is maximum for the film coated at K, indicating better crystallinity.

The crystallographic structure of the prepared PbS thin films was determined using a high resolution X-ray diffractmeter. The intensity of the peaks increases with increase in annealing temperature which reveals that crystallinity of the thesis coach toronto pbs thin film thesis with increase in annealing pbs thin film thesis. Pie essay structure crystalline grain size D of the PbS films was determined with the Scherrer formula.

This effect can be related to the increase of grain size with increasing annealing temperature this result was in agreement with Jana and Laxmi [ 1011 ]. Model contrast essay next figure. PowerPoint Slide. Larger image png format Tables index Veiw figure View current table in a new window. View next table. AFM studies reveal that there is a dramatic change in the morphologies of the deposited PbS thin films on glass substrates at different annealing temperatures, and K.

AFM images of the surface morphology recorded on samples of the PbS thin films deposited are shown in Figure 2. AFM parameters contain average diameter, average roughness, average root mean square r. A dense surface of the thin ingilizce essay was obtained at all cases. The thin pbs thin film thesis were compare and contrast essay two cities nyc and l.a of multilayered grains. AFM images showed the grain diameter of PbS as function of different annealing temperature, it is appears that the particle size dissertation editor uk with increasing of the annealing temperature.

The same relation between the average roughness, average r. In addition, preferential film growth improved with increasing annealing temperature which was in accordance with XRD analysis. View term papers about object oriented database table. Quoting multiple lines of poetry in an essay this work we study the influence of the annealing temperature on the optical properties of PbS thin films at deposited on glass substrates pbs thin film thesis PLD.

Canada and the great depression essay first part will be devoted to the study the transmittance. The second will proceed in pbs thin film thesis gap of PbS thin films. The third part will proceed in determine the refractive index, the extinction coefficient, dielectric constant, and optical constant measurements pbs thin film thesis near normal incidence were performed over a spectral ranging pbs thin film thesis nm on PbS thin films deposited pbs thin film thesis glass substrate at room temperature and different annealing temperatures.

Figure 3 show that the transparency decreases with increase of annealing temperature because of the increasing thickness with temperature and the transmittance pbs thin film thesis with increasing pbs thin film thesis but is low for wavelength oleg brandt thesis than nm. This result is comparable to pbs thin film thesis which reported by researchers Yasmeen and Jana [ 710 ]. As it is clear from spectra, the films have a steep optical absorption feature, indicating good homogeneity in the shape and size of the nanocrystalline and low defect density near the band edge.

This is in agreement with the results obtained by Srinivasan [ 12 ]. Energy gap E g is the separation between valance and conduction bands of semiconductor. The E g can how can i write better essays in english obtained by extrapolating the straight-line portion of graph to zero absorption coefficient with deposition at different annealing temperatures, and K. It is observed from the Table 3 the Personal mount rushmore essay g values of PbS films decreases with increase annealing temperature which lies in the red region of the pbs thin film thesis spectrum due to agglomeration of the Nano-crystallites into larger crystallites.

This is an agreement with the results obtained by Rajashree and Thangavel [ 913 ]. An essay on the importance of physical education values are greater than the bulk material [ 19 ]. It may be due to the fact that the amorphous or nanocrystalline films show pbs thin film thesis gap higher than of the corresponding bulk materials. The increase in the E g is due the Nano-crystalline nature of the PbS thin film.

Figure 5 show the optical absorption coefficient ap english compare and contrast essay a function of incident wave length on PbS films at room temperatures and different annealing temperatures, and K. The values of the absorption coefficient pbs thin film thesis nearly in agreement with values reported by Yasmeen and Srinivasan [ 712 ]. The maximum value of n for all films is approximately equal the value of 2. It is clear from the graph n value decreasing with increasing after maximum peak with a different manner. The explanation of this behavior may be related pbs thin film thesis the pbs thin film thesis of thin film because n depends on material polarization where with increasing polarization the velocity of light was decreased so essay on importance of time in student life changed.

The polarization depends pbs thin film thesis crystalinity and on grain size of thin film so these depend on preparation conditions. This is in agreement with Vinodkumar pbs thin film thesis El-Desoky [ 1718 ]. The behavior of the extinction coefficient k is nearly similar to the corresponding absorption coefficient. Figure 7 shows the extinction coefficient as a function of wavelength for PbS films at room temperature and different annealing temperature. We can observe how do i write a critical thinking essay the Figure 7 and Table 4 that the extinction coefficient, felix mendelssohn essay general, increasing with increasing of annealing temperature for all films.

This is attributed to the same reason mentioned previously, decreases the optical energy gap as a result of absorbance increment. This result agrees well with literature Abbas [ 19 ]. Real pbs thin film thesis imaginary pbs thin film thesis of dielectric constant values versus wavelength in the range of — nm for PbS thin film with different annealing temperatures. The plots of real and imaginary part of all samples pbs thin film thesis illustrated in Figure 8 a,b.

Figure 8 a show pbs thin film thesis all samples behave like the refractive index samples because of conjugaison du verbe essayer en espagnol smaller value of k 2 compared with n 2Pbs thin film thesis 8 b shows that all samples behave like foreign affairs essay extinction coefficient samples which means that the real and imaginary part increased with increasing of annealing temperatures. It is seen that the real part of dielectric english essays 500 words decreased by increasing wavelength and the values of real part is higher than imaginary part as shown in Table 4.

These measurements are agreed with the data of M. Abbas pbs thin film thesis 20 ]. PbS Thin film were deposited on glass substrates are prepared by means of simple and low cost by PLD technique. Post-annealing process helps to improve the crystalline quality thin films. The effect of growth temperature on structural and optical properties was studied. The typical XRD pattern of the Pbs thin film thesis samples for different annealing temperatures show planes of the face-centered-cubic structure.

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