Fabrication of Thin Films by Pulsed Laser Deposition for Clean Energy Applications

Fabrication of Thin Films by Pulsed Laser Deposition for Clean Energy Applications PDF Author: Xiaojun Zhang
Publisher:
ISBN:
Category :
Languages : en
Pages : 79

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Book Description
Pulsed laser deposition (PLD) is a physical vapor deposition technique for thin film fabrication. Compared with other techniques, pulsed laser deposition technique has advantages such as stoichiometry, flexibility, versatility, lower deposition temperature, ability to grow metastable materials. Because of these advantages, pulsed laser deposition has been widely used in materials research. In this dissertation, pulsed laser deposition has been used to grow thin films for solid oxide fuel cell, light-emitting diode, and solar cell applications. Firstly, yttria-stabilized zirconia (YSZ) and cerium dioxide (CeO2) thin films are deposited in oxygen-deficient environments; their properties are compared to those deposited in oxygen-rich environments. Oxygen-deficient films are highly (001)-oriented, which corresponds to a surface that is expected to be forbidden based on Tasker's theoretical calculation of stoichiometric ionic crystals. A model considering non-stoichiometry-induced surface relaxation and surface atomic density is proposed to explain the orientation phenomenon observed under oxygen-deficient deposition conditions. This model is consistent with previous experimental results for indium tin oxide (ITO), SnO2 and NiO thin films deposited under similar conditions. Detailed studies of the preferred orientation of these oxygen-deficient ionic crystals are of direct relevance to the fabrication of films for use in solid oxide fuel cells. Secondly, undoped, Cu-doped, Se-enriched, Cu2Se-doped, Ag-doped, Ag2Se-doped, and nitrogen-doped ZnSe films have been grown on fused quartz substrates by pulsed laser deposition. It is found that adding a small amount (~2 mol%) of Cu2Se can significantly improve crystallinity and (111) texturing of ZnSe films. While the other films are highly resistive, Cu2Se-doped ZnSe films are p-type conducting with hole concentrations of ~ cm-3 and resistivity of ~0.098 ohm*cm (compared with previous reports of ~ cm-3 and 0.75 ohm*cm, respectively). The successful heavy p-type doping of ZnSe films is attributed to substitution of Zn atoms with Cu while limiting selenium-vacancy-associated compensating defects with additional selenium. Nitrogen doping has turned ZnSe films more favorable to wurtzite structures. Two newly observed Raman peaks at 555 cm-1 and 602 cm-1 are assigned to N local vibrational modes of hexagonal ZnSe structures. The nitrogen-doped ZnSe films are not conductive, which might be due to compensating defects arising from the presence of native defects or other impurities. This work is of importance to solve doping difficulties and contact problems of wide-bandgap semiconductors. Finally, batch growth of thin films by pulsed laser deposition has been tried. Using the natural temperature gradient, films with different deposition temperatures have been fabricated together. With change of deposition temperatures, ZnSe films are shown to have problems associated with crystalline defects, selenium loss, or phase separation. ZnSe films with improved crystallinity and no phase separation have been achieved using a 16 mol% Se enriched target. Multi-plume pulsed laser deposition has been proposed and discussed. With directionality of PLD plumes and non-uniformity of PLD films, this system is supposed to be more suitable for high-throughput compound thin film fabrication, which makes it very promising for efficient materials optimization and exploration. High-throughput fabrication of compound thin films has been successfully achieved using this system.

Fabrication of Thin Films by Pulsed Laser Deposition for Clean Energy Applications

Fabrication of Thin Films by Pulsed Laser Deposition for Clean Energy Applications PDF Author: Xiaojun Zhang
Publisher:
ISBN:
Category :
Languages : en
Pages : 79

Get Book Here

Book Description
Pulsed laser deposition (PLD) is a physical vapor deposition technique for thin film fabrication. Compared with other techniques, pulsed laser deposition technique has advantages such as stoichiometry, flexibility, versatility, lower deposition temperature, ability to grow metastable materials. Because of these advantages, pulsed laser deposition has been widely used in materials research. In this dissertation, pulsed laser deposition has been used to grow thin films for solid oxide fuel cell, light-emitting diode, and solar cell applications. Firstly, yttria-stabilized zirconia (YSZ) and cerium dioxide (CeO2) thin films are deposited in oxygen-deficient environments; their properties are compared to those deposited in oxygen-rich environments. Oxygen-deficient films are highly (001)-oriented, which corresponds to a surface that is expected to be forbidden based on Tasker's theoretical calculation of stoichiometric ionic crystals. A model considering non-stoichiometry-induced surface relaxation and surface atomic density is proposed to explain the orientation phenomenon observed under oxygen-deficient deposition conditions. This model is consistent with previous experimental results for indium tin oxide (ITO), SnO2 and NiO thin films deposited under similar conditions. Detailed studies of the preferred orientation of these oxygen-deficient ionic crystals are of direct relevance to the fabrication of films for use in solid oxide fuel cells. Secondly, undoped, Cu-doped, Se-enriched, Cu2Se-doped, Ag-doped, Ag2Se-doped, and nitrogen-doped ZnSe films have been grown on fused quartz substrates by pulsed laser deposition. It is found that adding a small amount (~2 mol%) of Cu2Se can significantly improve crystallinity and (111) texturing of ZnSe films. While the other films are highly resistive, Cu2Se-doped ZnSe films are p-type conducting with hole concentrations of ~ cm-3 and resistivity of ~0.098 ohm*cm (compared with previous reports of ~ cm-3 and 0.75 ohm*cm, respectively). The successful heavy p-type doping of ZnSe films is attributed to substitution of Zn atoms with Cu while limiting selenium-vacancy-associated compensating defects with additional selenium. Nitrogen doping has turned ZnSe films more favorable to wurtzite structures. Two newly observed Raman peaks at 555 cm-1 and 602 cm-1 are assigned to N local vibrational modes of hexagonal ZnSe structures. The nitrogen-doped ZnSe films are not conductive, which might be due to compensating defects arising from the presence of native defects or other impurities. This work is of importance to solve doping difficulties and contact problems of wide-bandgap semiconductors. Finally, batch growth of thin films by pulsed laser deposition has been tried. Using the natural temperature gradient, films with different deposition temperatures have been fabricated together. With change of deposition temperatures, ZnSe films are shown to have problems associated with crystalline defects, selenium loss, or phase separation. ZnSe films with improved crystallinity and no phase separation have been achieved using a 16 mol% Se enriched target. Multi-plume pulsed laser deposition has been proposed and discussed. With directionality of PLD plumes and non-uniformity of PLD films, this system is supposed to be more suitable for high-throughput compound thin film fabrication, which makes it very promising for efficient materials optimization and exploration. High-throughput fabrication of compound thin films has been successfully achieved using this system.

Organic Nanostructured Thin Film Devices and Coatings for Clean Energy

Organic Nanostructured Thin Film Devices and Coatings for Clean Energy PDF Author: Sam Zhang
Publisher:
ISBN:
Category : Coatings
Languages : en
Pages : 268

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Book Description


Pulsed Laser Deposition of AlMgB14 Thin Films

Pulsed Laser Deposition of AlMgB14 Thin Films PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 129

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Book Description
Hard, wear-resistant coatings of thin film borides based on AlMgB14 have the potential to be applied industrially to improve the tool life of cutting tools and pump vanes and may account for several million dollars in savings as a result of reduced wear on these parts. Past work with this material has shown that it can have a hardness of up to 45GPa and be fabricated into thin films with a similar hardness using pulsed laser deposition. These films have already been shown to be promising for industrial applications. Cutting tools coated with AlMgB14 used to mill titanium alloys have been shown to substantially reduce the wear on the cutting tool and extend its cutting life. However, little research into the thin film fabrication process using pulsed laser deposition to make AlMgB14 has been conducted. In this work, research was conducted into methods to optimize the deposition parameters for the AlMgB14 films. Processing methods to eliminate large particles on the surface of the AlMgB14 films, produce films that were at least 1m thick, reduce the surface roughness of the films, and improve the adhesion of the thin films were investigated. Use of a femtosecond laser source rather than a nanosecond laser source was found to be effective in eliminating large particles considered detrimental to wear reduction properties from the films. Films produced with the femtosecond laser were also found to be deposited at a rate 100 times faster than those produced with the nanosecond laser. However, films produced with the femtosecond laser developed a relatively high RMS surface roughness around 55nm. Attempts to decrease the surface roughness were largely unsuccessful. Neither increasing the surface temperature of the substrate during deposition nor using a double pulse to ablate the material was found to be extremely successful to reduce the surface roughness. Finally, the adhesion of the thin films to M2 tool steel substrates, assessed using the Rockwell C indentation adhesion test, was found to be substantially improved by the deposition of a titanium interlayer, but unaffected by increasing the temperature of the substrates. The titanium was found to improve the adhesion strength of the films because it reacted with both the steel and the AlMgB14 compound to form new compounds. Ultimately, it was concluded that the films with the best properties were produced with a femtosecond pulsed laser and were deposited on top of a titanium interlayer to improve the thin film adhesion.

Intermediate-Temperature Solid Oxide Fuel Cells

Intermediate-Temperature Solid Oxide Fuel Cells PDF Author: Zongping Shao
Publisher: Springer
ISBN: 366252936X
Category : Technology & Engineering
Languages : en
Pages : 271

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Book Description
This book discusses recent advances in intermediate-temperature solid oxide fuel cells (IT-SOFCs), focusing on material development and design, mechanism study, reaction kinetics and practical applications. It consists of five chapters presenting different types of reactions and materials employed in electrolytes, cathodes, anodes, interconnects and sealants for IT-SOFCs. It also includes two chapters highlighting new aspects of these solid oxide fuel cells and exploring their practical applications. This insightful and useful book appeals to a wide readership in various fields, including solid oxide fuel cells, electrochemistry, membranes and ceramics. Zongping Shao is a Professor at the State Key Laboratory of Materials-Oriented Chemical Engineering and the College of Energy, Nanjing University of Technology, China. Moses O. Tade is a Professor at the Department of Chemical Engineering, Curtin University, Australia.

Thin Films

Thin Films PDF Author: Dongfang Yang
Publisher: BoD – Books on Demand
ISBN: 1803564555
Category : Technology & Engineering
Languages : en
Pages : 224

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Book Description
A thin film is a layer of material ranging from fractions of a nanometer to several micrometers in thickness. Thin films have been employed in many applications to provide surfaces that possess specific optical, electronic, chemical, mechanical and thermal properties. Through ten chapters consisting of original research studies and literature reviews written by experts from the international scientific community, this book covers the deposition and application of thin films.

Handbook of Laser Micro- and Nano-Engineering

Handbook of Laser Micro- and Nano-Engineering PDF Author: KOJI SUGIOKA.
Publisher:
ISBN: 9783319695372
Category : Lasers in engineering
Languages : en
Pages :

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Book Description
This handbook provides a comprehensive review of the entire field of laser micro and nano processing, including not only a detailed introduction to individual laser processing techniques but also the fundamentals of laser-matter interaction and lasers, optics, equipment, diagnostics, as well as monitoring and measurement techniques for laser processing. Consisting of 11 sections, each composed of 4 to 6 chapters written by leading experts in the relevant field. Each main part of the handbook is supervised by its own part editor(s) so that high-quality content as well as completeness are assured. The book provides essential scientific and technical information to researchers and engineers already working in the field as well as students and young scientists planning to work in the area in the future. Lasers found application in materials processing practically since their invention in 1960, and are currently used widely in manufacturing. The main driving force behind this fact is that the lasers can provide unique solutions in material processing with high quality, high efficiency, high flexibility, high resolution, versatility and low environmental load. Macro-processing based on thermal process using infrared lasers such as CO2 lasers has been the mainstream in the early stages, while research and development of micro- and nano-processing are becoming increasingly more active as short wavelength and/or short pulse width lasers have been developed. In particular, recent advances in ultrafast lasers have opened up a new avenue to laser material processing due to the capabilities of ultrahigh precision micro- and nanofabrication of diverse materials. This handbook is the first book covering the basics, the state-of-the-art and important applications of the dynamic and rapidly expanding discipline of laser micro- and nanoengineering. This comprehensive source makes readers familiar with a broad spectrum of approaches to solve all relevant problems in science and technology. This handbook is the ultimate desk reference for all people working in the field.

Thin Film Structures in Energy Applications

Thin Film Structures in Energy Applications PDF Author: Suresh Babu Krishna Moorthy
Publisher: Springer
ISBN: 3319147749
Category : Technology & Engineering
Languages : en
Pages : 300

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Book Description
This book provides a comprehensive overview of thin film structures in energy applications. Each chapter contains both fundamentals principles for each thin film structure as well as the relevant energy application technologies. The authors cover thin films for a variety of energy sectors including inorganic and organic solar cells, DSSCs, solid oxide fuel cells, thermoelectrics, phosphors and cutting tools.

Thin Films, Atomic Layer Deposition, and 3D Printing

Thin Films, Atomic Layer Deposition, and 3D Printing PDF Author: Kingsley Ukoba
Publisher: CRC Press
ISBN: 1000999203
Category : Technology & Engineering
Languages : en
Pages : 315

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Book Description
Thin Films, Atomic Layer Deposition, and 3D Printing explains the concept of thin films, atomic layers deposition, and the Fourth Industrial Revolution (4IR) with an aim to illustrate existing resources and give a broader perspective of the involved processes as well as provide a selection of different types of 3D printing, materials used for 3D printing, emerging trends and applications, and current top-performing 3D printers using different technologies. It covers the concept of the 4IR and its role in current and future human endeavors for both experts/nonexperts. The book includes figures, diagrams, and their applications in real-life situations. Features: Provides comprehensive material on conventional and emerging thin film, atomic layer, and additive technologies. Discusses the concept of Industry 4.0 in thin films technology. Details the preparation and properties of hybrid and scalable (ultra) thin materials for advanced applications. Explores detailed bibliometric analyses on pertinent applications. Interconnects atomic layer deposition and additive manufacturing. This book is aimed at researchers and graduate students in mechanical, materials, and metallurgical engineering.

Fabrication of Polycrystalline Thin Films by Pulsed Laser Processing

Fabrication of Polycrystalline Thin Films by Pulsed Laser Processing PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
A method for fabricating polycrystalline thin films on low-temperature (or high-temperature) substrates which uses processing temperatures that are low enough to avoid damage to the substrate, and then transiently heating select layers of the thin films with at least one pulse of a laser or other homogenized beam source. The pulse length is selected so that the layers of interest are transiently heated to a temperature which allows recrystallization and/or dopant activation while maintaining the substrate at a temperature which is sufficiently low to avoid damage to the substrate. This method is particularly applicable in the fabrication of solar cells.

Film Synthesis and Growth Using Energetic Beams: Volume 388

Film Synthesis and Growth Using Energetic Beams: Volume 388 PDF Author: H. A. Atwater
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 472

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Book Description
With over 16 countries represented, this book represents international developments in the field of film synthesis and growth using energetic beams. It focuses on pulsed-laser deposition. Fundamental issues pertaining to the generation of laser ablation plumes, temperature distributions and collisional effects are described. Ion-assisted pulsed-laser deposition, pulsed-ion deposition, applications of hyperthermal beams and aspects of surface dynamics are discussed. The inclusion of an ion beam with the ablation process leads to some unique modifications in the thin-film growth mechanisms, and hence, film properties. Likewise, the collision of high-mass metal cluster ions with substrates shows promise for growth of novel structures. Also featured are new developments of optoelectronic materials, nitrides and carbon films using a variety of techniques. The effects of beam-induced defects on growth and surface morphology, chemical effects during growth, and characterization of film growth and film properties are addressed.