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 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 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 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 Molecular Ink Processed Iron Pyrite Thin Films for Photovoltaics written by Amanda Sue Weber and published by . This book was released on 2015 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thin-film photovoltaics (PV) have the potential to supply our future energy needs, but the dominant commercial thin film technologies rely on rare or toxic elements that may limit their capacity to scale to the terawatt levels of electricity generation needed to impact global energy demand. Iron pyrite (FeS2) is a promising, earth-abundant material that has a suitable band gap of 0.95 eV, a large optical absorption coefficient, and adequate carrier diffusion lengths for use in PV. Unfortunately pyrite solar cells have suffered from low open circuit voltages that hinder overall device performance. Developing high quality, phase pure pyrite thin films may be the key to overcoming these performance drawbacks. A solution-based process using elemental precursors dissolved in hydrazine has been previously developed at IBM for fabricating solar absorbers such as copper zinc tin selenide/sulfide (CZTS) and copper indium gallium selenide/sulfide (CIGS). Devices using these films have achieved 12.6% and 15.2% efficiencies respectively. In this dissertation, a hydrazine-free molecular ink that uses common organic solvents to dissolve elemental iron and sulfur is described for making pyrite thin films. To form pyrite thin films, the molecular ink is deposited onto molybdenum-coated glass and then annealed at temperatures between 350-500°C in both hydrogen sulfide and sulfur vapor atmospheres. Phase purity is confirmed using X-ray diffraction and Raman spectroscopy. Film morphology is examined with scanning electron microscopy. Elemental composition is analyzed using secondary ion mass spectrometry and FT-IR spectroscopy. Optical properties are measured using an integrating sphere attachment on a UV-VIS spectrometer. The electrical properties of the films are characterized by temperature-dependent resistivity and qualitative thermopower to verify the carrier type. The resulting films are measured to be pure phase pyrite that consist of well-connected grains between 50-200 nm in size and are free of pinholes. Optical and electrical properties agree with those commonly cited in literature. Elemental analysis reveals low amounts of oxygen and carbon impurities, compared to other fabrication methods of pyrite used in the same laboratory. The initial results of using these films in p-n heterojunctions will be presented along with on-going strategies being researched to overcome new challenges..

Download or read book Solar Energy Conversion and Storage written by Suresh C. Ameta and published by CRC Press. This book was released on 2015-11-05 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solar Energy Conversion and Storage: Photochemical Modes showcases the latest advances in solar cell technology while offering valuable insight into the future of solar energy conversion and storage. Focusing on photochemical methods of converting and/or storing light energy in the form of electrical or chemical energy, the book:Describes various t

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 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 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 Advanced Energy Materials written by Ashutosh Tiwari and published by John Wiley & Sons. This book was released on 2014-02-12 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: An essential resource for scientists designing new energy materials for the vast landscape of solar energy conversion as well as materials processing and characterization Based on the new and fundamental research on novel energy materials with tailor-made photonic properties, the role of materials engineering has been to provide much needed support in the development of photovoltaic devices. Advanced Energy Materials offers a unique, state-of-the-art look at the new world of novel energy materials science, shedding light on the subject’s vast multi-disciplinary approach The book focuses particularly on photovoltaics, efficient light sources, fuel cells, energy-saving technologies, energy storage technologies, nanostructured materials as well as innovating materials and techniques for future nanoscale electronics. Pathways to future development are also discussed. Critical, cutting-edge subjects are addressed, including: Non-imaging focusing heliostat; state-of-the-art of nanostructures Metal oxide semiconductors and their nanocomposites Superionic solids; polymer nanocomposites; solid electrolytes; advanced electronics Electronic and optical properties of lead sulfide High-electron mobility transistors and light-emitting diodes Anti-ferroelectric liquid crystals; PEEK membrane for fuel cells Advanced phosphors for energy-efficient lighting Molecular computation photovoltaics and photocatalysts Photovoltaic device technology and non-conventional energy applications Readership The book is written for a large and broad readership including researchers and university graduate students from diverse backgrounds such as chemistry, materials science, physics, and engineering working in the fields of nanotechnology, photovoltaic device technology, and non-conventional energy.

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 Thin Films for Energy Harvesting Conversion and Storage written by Zhong Chen and published by MDPI. This book was released on 2019-11-07 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: Efficient clean energy harvesting, conversion, and storage technologies are of immense importance for the sustainable development of human society. To this end, scientists have made significant advances in recent years regarding new materials and devices for improving the energy conversion efficiency for photovoltaics, thermoelectric generation, photoelectrochemical/electrolytic hydrogen generation, and rechargeable metal ion batteries. The aim of this Special Issue is to provide a platform for research scientists and engineers in these areas to demonstrate and exchange their latest research findings. This thematic topic undoubtedly represents an extremely important technological direction, covering materials processing, characterization, simulation, and performance evaluation of thin films used in energy harvesting, conversion, and storage.

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 Iron Pyrite Absorbers for Solar Photovoltaic Energy Conversion written by Moritz Limpinsel and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Iron pyrite (cubic FeS2) is an earth-abundant, non-toxic semiconductor with great potential as an absorber material in future large-scale deployment of solar photovoltaic panels. The surprisingly small photo-voltage generated by this material (

Download or read book Nanostructured Oxide Thin Films Synthesized by Spray Pyrolysis written by Najoua Kamoun-Turki and published by . This book was released on 2018-03 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the spray pyrolysis technique that is used to produce thin films of metallic oxides on glass substrates. Also discussed are the process variables of the spray pyrolysis process used to manufacture specific structures such as nanostructured thin films.

Download or read book The Synthesis of Precursors for the Deposition of Photovoltaic Thin Films written by Anna Sudlow and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The work in the thesis describes attempts to synthesise precursors for the deposition of thin films for use in thin-film photovoltaic cells. Chapter One - Introduction provides a brief background to photovoltaic cells with specific detail given to thin-film photovoltaic cells. The concepts of chemical vapour deposition (CVD) and precursor design are discussed with relevant precursors are highlighted. Chapter Two - Xanthates provides details of the synthesis and characterisation of a series of metal xanthates. The materials chemistry of the xanthates is then discussed. Chapter Three - Dithiocarbamates provides details of the synthesis and characterisation of a series of metal dithiocarbamates. The materials chemistry of the dithiocarbamates is then discussed. Chapter Four - Materials Work on Cu2ZnSnS2 and CuSbS2 provides a discussion of attempts to deposit thin films of Cu2ZnSnS4 and CuSbS2 from the precursors discussed in chapters two and three. Chapter Five - Heterobimetallic precursors provides details of the synthesis and characterisation of a series of heterobimetallic precursors liked by chlorine bridges and subsequent attempts to replace the chlorine atoms with thiolate ligands. Chapter Six - Precursors for ZnO:F provides details of the synthesis and characterisation of a series of single source precursors designed for the deposition of ZnO:F thin films. The materials chemistry and subsequent CVD trials are then discussed.

Download or read book Synthesis and Characterization of Iron Oxide Thin Films for Use in Electrical Devices written by and published by . This book was released on 2013 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have developed a novel method of preparation of homogeneous transparent iron oxide thin films based on the thermal decomposition of iron tris-2,2'-bipyridine complexes. The resulting films were characterized with optical spectroscopy, optical and scanning electron microscopy and their crystal structure was established with X-ray powder diffraction and Raman spectroscopy. The film morphology is defined by the choice of the iron precursor and the method allows for both mono- and multilayer deposition, effectively providing control over film thickness. Addition of tris-2,2'-bipyridine complexes of other metals on the stage of film deposition provides a convenient path towards film doping. Obtained iron oxide films were also tested as photoanodes in dye-sensitized solar cells.