Download or read book Synthesis and Characterization of Pyrite Thin Films and Single Crystals for PV Devices and Fundamental Studies written by Nima Farhi and published by . This book was released on 2016 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt: Iron pyrite is an earth-abundant, non-toxic, and inexpensive semiconductor that has the potential to produce large photocurrents in photovoltaic devices. However, the efficiency of pyrite solar cell devices has been limited by its photovoltage (

Download or read book Growth and Characterization of Iron Pyrite Thin Films and Single Crystals for Applications in Photovoltaics written by Nicholas Eli Berry and published by . This book was released on 2012 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: Iron pyrite (FeS2) is a promising earth abundant semiconductor for applications in thin film photovoltaics. This thesis focuses on the growth and characterization of pyrite thin films and single crystals. Single phase, large grain, and uniform polycrystalline pyrite thin films are fabricated on glass and molybdenum coated glass substrates by atmospheric-pressure chemical vapor deposition using the reaction of iron (III) acetylacetonate and tert-butyl disulfide in argon at 300°C, followed by sulfur annealing at 500-550°C to convert marcasite impurities to pyrite. Large, pure phase, and high quality pyrite single crystals were grown using a Na2S based flux growth technique. Thin films and single crystals were characterized by numerous techniques including X-ray diffraction, Raman spectroscopy and Hall effect measurements. The films exhibit low mobility, high carrier concentration p-type behavior while the single crystals exhibit high mobility, low carrier concentration n-type behavior, consistent with literature. The temperature dependence of the hall coefficient of single crystals shows the first clear transition from n-type behavior at room temperature to p-type behavior at low temperatures in pyrite. In addition, simple polishing of the surface is shown to modify the concentration of holes, demonstrating that p-type carriers can originate from the surface of a high quality pyrite single crystal.

Download or read book Pyrite Thin Films written by Sean Michael Seefeld and published by . This book was released on 2012 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work in this thesis includes a combination of four methods and applications for pyrite thin films produced via solution based processes. Chapter 1 provides a brief introduction into earth abundant materials for photovoltaic applications. The issue of supply and price constraints is explored, and the motivation for pyrite thin films is explained. The fundamental properties of pyrite are provided along with a synopsis of previous pyrite device constructions and results. Chapter 2 discusses the synthesis and characterization of phase-pure, single-crystalline, and clustered FeS2 nanocrystals synthesized in a one-pot "heat-up" synthesis. The NCs were then subjected to ligand removal with hydrazine to form polycrystalline pyrite thin films by sintering these layers of NCs at 450-600° under a sulfur atmosphere. The sintering behavior and precursor chemistry are explored. Chapter 3 discusses the synthesis and characterization of phase-pure, single-crystalline, and well-dispersed colloidal FeS2 nanocrystals (NCs) synthesized in high yield by a simple hot-injection route in octadecylamine. The NCs were then subjected to partial ligand exchange with octadecylxanthate to yield stable pyrite NC inks. Polycrystalline pyrite thin films were fabricated by sintering layers of these NCs at 450-600°C under a sulfur atmosphere. Chapter 4 briefly covers the application of the FeS2 nanocrystals used in lithographically patterned microfluidic devices. Nanocrystals are solution deposited inside lithographically patterned channels on glass substrates. Subsequent ligand exchanges inside these channels allow for use of these patterned nanocrystal channels to develop microfluidic devices for DNA protein interaction footprinting. Chapter 5 reports on solution-deposited, single-phase, large-grain, and uniform polycrystalline iron pyrite (FeS2) thin films fabricated on quartz and molybdenum-coated glass substrates from an iron (III) acetylacetonate molecular ink. The ink, prepared as a viscous solution of Fe(acac)3 and sulfur in pyridine, is spin coated and baked in air utilizing a layer by layer process to produce ~300 nm thick, mixed-phase pyrite/marcasite thin films after annealing in H2S atmosphere. A second annealing step in sulfur vapor at 450-600°C yields phase-pure pyrite films with suitable morphology and mechanical properties for use in solar cells. The resulting pyrite films are characterized by X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), secondary ion mass spectrometry (SIMS), optical absorption spectroscopy, and variable-temperature Hall effect measurements.

Download or read book Growth and Characterization of Pyrite Thin Films for Photovoltaic Applications written by Alex Wertheim and published by . This book was released on 2014 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: A series of pyrite thin films were synthesized using a novel sequential evaporationtechnique to study the effects of substrate temperature on deposition rate and micro-structure ofthe deposited material. Pyrite was deposited in a monolayer-by-monolayer fashion usingsequential evaporation of Fe under high vacuum, followed by sulfidation at high S pressures(typically> 1 mTorr to 1 Torr). Thin films were synthesized using two different growth processes; aone-step process in which a constant growth temperature is maintained throughout growth, and athree-step process in which an initial low temperature seed layer is deposited, followed by a hightemperature layer, and then finished with a low temperature capping layer. Analysis methods toanalyze the properties of the films included Glancing Angle X-Ray Diffraction (GAXRD), Rutherford Back-scattering Spectroscopy (RBS), Transmission Electron Microscopy (TEM), Secondary Ion Mass Spectroscopy (SIMS), 2-point IV measurements, and Hall effectmeasurements. Our results show that crystallinity of the pyrite thin film improves and grain sizeincreases with increasing substrate temperature. The sticking coefficient of Fe was found toincrease with increasing growth temperature, indicating that the Fe incorporation into the growingfilm is a thermally activated process.

Download or read book Pyrite written by Noel Whitley and published by Nova Science Pub Incorporated. This book was released on 2012-12-20 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pyrite is a widely spread natural mineral and important organic material. It participates in numerous geochemical processes, including oxidation reactions that cause acid mine drainage. In this book, the authors discuss pyrites synthesis, characterisation and uses. Topics include the use of pyrite as a concentrator of gold in laboratory and natural systems; oxidative degradation of organic pollutants by fenton reaction in pyrite suspension; potentiometric characterisation and analytical application of pyrite mineral for the assay of weak organic acids in non-aqueous media; sorption of mercury(II) to synthesised pyrite (FES2) and stabilisation via surface reaction; the pyritisation of fossils from the cretaceous period of the Langerstatte Araripe Basin, in Northeast Brazil; and pyrite phases as high pressure polymorphs of dioxides and other compounds.

Download or read book Synthesis and Analysis of Thin Films for Perovskite Solar Cells written by Alexander Klasen and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Study on the Synthesis of Iron Pyrite Thin Films for Use as a Photovoltaic Absorber written by Amitabha Sarkar and published by . This book was released on 2014 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although iron pyrite had been identified as a novel photo-voltaic material, it is yet to be harnessed. Iron pyrite forms mechanically unstable films with pinholes. A simple method has been devised to greatly improve the mechanical stability of iron pyrite thin films grown on quartz. This is done by annealing the precursor films prior to sulfurizing in vacuum-sealed quartz tubes. It has also been shown that an equilibrium based process is necessary to synthesize films of good quality. Zinc was successfully incorporated into iron pyrite thin films to increase the bandgap by 0.1 eV. The electronic properties of these films are similar to that found in literature. It has been identified that cracks in the film and voids between the grains are the cause for poor electronic properties. Composition analysis showed a high degree of oxygen contamination in iron precursor films resulting in poor electronic properties of iron pyrite films obtained by sulfuring the precursor films. Thus it may be possible to synthesize high quality films if these issues are addressed.

Download or read book Revolution of Perovskite written by Narayanasamy Sabari Arul and published by Springer Nature. This book was released on 2020-01-03 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents advanced synthesis techniques for fabricating Perovskite materials with enhanced properties for applications such as energy storage devices, photovoltaics, electrocatalysis, electronic devices, photocatalysts, sensing, and biomedical instruments. The book attempts to fill a gap in the published literature and provide a detailed reference on Perovskite materials. This book will be of use to graduate students and academic and industrial researchers in the fields of solid-state chemistry, physics, materials science, and chemical engineering.

Download or read book Synthesis and Characterization of Iron Pyrite Nanocrystals for Photovoltaic Devices written by Scott Curtis Mangham and published by . This book was released on 2013 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: Iron pyrite nanocrystals have been synthesized using a hot-injection method with a variety of amines and characterized with properties necessary for photovoltaic devices. The iron pyrite nanocrystals were characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, optical absorption, micro-Raman, and micro-Photoluminescence. The optical absorbance spectra showed the large absorption in the visible and near infrared spectral range for the nanocrystals as well as to show the band gap. The face-centered cubic crystal structure of the iron pyrite nanocrystals was shown by matching the measured X-ray diffraction pattern to a face-centered cubic iron pyrite reference pattern. Using Bragg's law and Scherrer's formula helps to calculate the grain size and lattice spacing based upon the X-ray diffraction pattern. The scanning electron microscopy produces images that show the particle size of the nanocrystals while the transmission electron microscopy produced images that show the lattice spacing and grain size for the iron pyrite nanocrystals that are compared to the previously mentioned calculated grain size and lattice spacing. The micro-Raman and micro-Photoluminescence are used to compare the synthesized iron pyrite nanocrystals to natural-bulk iron pyrite. The micro-Photoluminescence is also used to calculate a band gap and compare this band gap to the one obtain by the optical absorbance spectra.

Download or read book Solution based Syntheses of Iron Pyrite Thin Films for Photovoltaic and Protein Foot printing Applications written by Mohammed El Makkaoui and published by . This book was released on 2015 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Iron pyrite (cubic FeS2) is a non-toxic, earth abundant semiconductor possessing a set of excellent optical/electronic properties for serving as an absorber layer in PV devices. Additionally, pyrite is a very efficient hydroxyl radical generator via Fenton chemistry and has shown promise in oxidative protein and DNA foot-printing application. The main focus of this thesis is on fabricating phase and elementally pure iron pyrite thin films using a solution-based approach that employs hydrazine as a solvent. A precursor ink is formed at room temperature by mixing elemental iron and sulfur in anhydrous hydrazine and then deposited on Mo-coated glass substrates, via spin coating, to yield amorphous iron sulfide films that are then annealed in H2S (340 o C) and sulfur gas (less than or equal 500 °C) to form uniform, polycrystalline and phase pure pyrite films with densely packed grains. This approach is likely to yield the most elementally pure pyrite thin films made to date, through a very simple and scalable process. The ink has shown to be very sensitive to environmental conditions and has a very short shelf life (~1 day). Additionally, the film microstructure is greatly influenced by the S:Fe concentration ratio that when tuned to 3:1, yielded uniform, robust and optically flat iron sulfide thin films with an optimal thickness (~320 nm) for PV application. The results however were not reproducible, mainly due to failure in applying multiple layers without compromising film morphology. Thinner ( 100 nm) iron sulfide films, on the other hand, are reproducibly produced, but are too thin to be employed in PV devices. Direct annealing in sulfur gas at 475 °C for 4 hours, bypassing the 12 hour H2S annealing step, yielded phase pure pyrite films, with good morphology, at lower processing time and annealing temperatures (

Download or read book Preparation of Iron Pyrite Films for Solar Cells by Metalorganic Chemical Vapor Deposition microform written by Prasad Narhar Gadgil and published by National Library of Canada = Bibliothèque nationale du Canada. This book was released on 1990 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis of Freestanding Single crystal Perovskite Films and Heterostructures by Etching of Sacrificial Water soluble Layers written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The ability to create and manipulate materials in two-dimensional (2D) form has repeatedly had transformative impact on science and technology. In parallel with the exfoliation and stacking of intrinsically layered crystals, atomic-scale thin film growth of complex materials has enabled the creation of artificial 2D heterostructures with novel functionality and emergent phenomena, as seen in perovskite heterostructures. However, separation of these layers from the growth substrate has proven challenging, limiting the manipulation capabilities of these heterostructures with respect to exfoliated materials. Here we present a general method to create freestanding perovskite membranes. The key is the epitaxial growth of water-soluble Sr3Al2O6 on perovskite substrates, followed by in situ growth of films and heterostructures. Millimetre-size single-crystalline membranes are produced by etching the Sr3Al2O6 layer in water, providing the opportunity to transfer them to arbitrary substrates and integrate them with heterostructures of semiconductors and layered compounds.

Download or read book Chemical Solution Deposition and Advanced Characterization of Pb free Bi based Piezoelectric Thin Films written by Ashley D. Mason and published by . This book was released on 2016 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: Piezoelectric materials convert mechanical strain into a dielectric displacement, as well as the converse, allowing these materials to be used as sensors, actuators, and transducers. Currently, lead zirconate titanate (PZT) is the primary material used in these applications. Due to environmental toxicity and safety concerns associated with Pb, development of alternative materials is necessary. Bi-based systems are an attractive area of research in both bulk ceramic and thin film embodiments. Although progress in developing bismuth sodium titanate (BNT)-based solid solutions has been impressive, the combination of cation volatility and high processing temperatures for both bulk ceramic and thin film fabrication can lead to changes in stoichiometry and create defects within the system which can significantly impact material properties. One of the main sources of defects is often presumed to be related to cation volatility. As such, the diffusion behavior of volatile cations within BNT-bismuth potassium titanate (BKT)-based thin films was studied using transmission electron microscopy, electron energy loss spectroscopy, and energy dispersive x-ray spectroscopy. Both in-situ and ex-situ experiments were performed where the objectives were to: (1) observe crystallization processes in a single layer film, and (2) map the locations of Bi, Na, and K throughout the thin film, bottom electrode, and substrate cross-section. Results indicated that Bi, Na, and K had all diffused into the Pt bottom electrode, and in some cases the underlying buffer layers. In addition to the aforementioned volatilization into atmosphere, this diffusion could also impact film stoichiometry and material properties and should be accounted for. Multi-layer BNT-BKT-bismuth zinc titanate (BZnT) thin films were fabricated via chemical solution deposition. X-ray diffraction and atomic force microscopy were used to study structure and morphology changes with processing parameters. The dielectric, ferroelectric,and piezoelectric properties were characterized and values of the effective out-of-plane piezoelectric coefficient, d33,f, were extracted from double beam laser interferometry measurements. Dielectric constants and loss ranged from 380-800 and 2-8% respectively as a function of thin film composition. For 0.8 mm diameter top electrodes, the maximum value measured for effective d33,f was approximately 80 pm/V. Lastly, electrical fatigue measurements showed that while the effective d33,f was larger for compositions closer to the BNT-BKT morphotropic phase boundary (MPB), those further away were able to withstand a higher number of cycles, up to three orders of magnitude, at ± 400 kV/cm. Results from this dissertation were: (i) An increase in the number of possible end members (e.g. BZnT, BMgT, BaTiO3 (BT)) for BNT-BKT-based thin films fabricated at OSU (ii) An expansion in the range of compositions fabricated rather than commonly studied MPB compositions: while the maximum observed values for effective d33 in bulk BNT-BKTBZnT were further towards the BKT-rich side of the ternary phase diagram, the same is not true in thin films (iii) Motivation for further study of the diffusion of volatile cations in BNT-based thin film systems: cations are not only volatilized into atmosphere during high temperature processing, but can also diffuse out of the thin film into and through the bottom electrode (iv) If longer device lifetime supercedes the need for the highest obtainable piezoelectric coefficients, compositions away from the BNT-BKT MPB may be of interest.

Download or read book Synthesis and Properties of Ferroelectric Perovskite Oxide Thin Films written by Andrei Akbasheu and published by . This book was released on 2015 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: The growth of oxide thin films has long been of great interested for materials scientists for the application in advanced technologies such as nanoelectronics, photovoltaics and sensors. Atomic layer deposition (ALD) is known for being a non-expensive, low-vacuum and low-temperature deposition method able to conformally coat even high-aspect-ratio materials and structures. ALD has been mainly applied to prepare binary oxides such as ZnO and TiO2, and the synthesis of functional complex oxides such as BiFeO3 and CoFe2O4 has little been studied. In the first part of this work, the application of ALD to the preparation of complex oxide thin films based on the Bi-Fe-O system is explored. The important aspects of the ALD approach such as (a) the growth of amorphous Bi-Fe-O by ALD, (b) the epitaxial crystallization of the multiferroic perovskite BiFeO3 films on different substrates, (c) appearance of impurity phases in the films are addressed. Ultimately, the dissertation aims at dispelling the widely held notion that atomic layer deposition is not appropriate for attaining high-quality chemically complex oxide films in the epitaxial form, demonstrating the applicability as an inexpensive, facile, and highly scalable route. The second part of this work is devoted to the preparation and characterization of new ferroelectric thin films as photovoltaic materials. Large optical band gaps of ferroelectric oxides make the optical absorption impractical for solar cell applications. Recently a new strategy for band gap lowering by doping the perovskite KNbO3 with Ba on the A-site and Ni on the B-site resulting in the generation of Ni2+-O vacancy pairs has been shown to significantly increase the optical absorption without loss of ferroelectricity. Using pulsed laser deposition, the synthesis approach to thin films of these new oxides was developed despite significant challenges for the stoichiometry control. The chemical doping approach to the reduction of the band gap was extended to produce new visible-light-absorbing ferroelectric thin films in another perovskite oxide. These materials showed a switchable photovoltaic effect under the visible light illumination along with the retention of the ferroelectric order. This dissertation demonstrates the feasibility of thin film deposition of aforementioned doped ferroelectric oxide perovskites and their ferroelectric photovoltaic properties, which can be extended to other ferroelectric oxides, and provide important information on the synthesis of such materials as thin films.

Download or read book Characterization Techniques for Perovskite Solar Cell Materials written by Meysam Pazoki and published by Elsevier. This book was released on 2019-11-18 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Characterization Techniques for Perovskite Solar Cell Materials: Characterization of Recently Emerged Perovskite Solar Cell Materials to Provide an Understanding of the Fundamental Physics on the Nano Scale and Optimize the Operation of the Device Towards Stable and Low-Cost Photovoltaic Technology explores the characterization of nanocrystals of the perovskite film, related interfaces, and the overall impacts of these properties on device efficiency. Included is a collection of both main and research techniques for perovskite solar cells. For the first time, readers will have a complete reference of different characterization techniques, all housed in a work written by highly experienced experts.

Download or read book Synthesis and Characterization of Chalcogenide Perovskites written by Stephen Andrew Filippone and published by . This book was released on 2021 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: This body of work advances the emerging field of chalcogenide perovskites by providing practical guides for thin film synthesis, lessons from thin film and bulk synthesis work, as well and basic property measurements on bulk material, critical for the design of future thin film devices.

Download or read book Energy Research Abstracts written by and published by . This book was released on 1978 with total page 1064 pages. Available in PDF, EPUB and Kindle. Book excerpt: