Electrochromic Properties of Vanadium Pentoxide Nanostructured Thin Films

Electrochromic Properties of Vanadium Pentoxide Nanostructured Thin Films PDF Author: Afaf Almoabadi
Publisher:
ISBN:
Category :
Languages : en
Pages : 92

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Book Description
ABSTRACT Electrochromic Properties of Vanadium Pentoxide Nanostructured Thin Films Afaf Almoabadi The focus of this work is the improvement of the electrochromic properties of vanadium pentoxide thin films in order to expand its use. Indeed, because of its rather poor electrochromic properties, until now, vanadium pentoxide has only been used as a storage material in an electrochromic device, in conjunction with tungsten oxide, molybdenum oxide etc. To this purpose, vanadium pentoxide thin films were prepared under different conditions and characterized by using optical and electrochemical methods. Films were deposited on indium tin oxide (ITO) substrates by dip-coating at both room- and sub-zero temperature (-100C) and porosity in the sol-gel prepared vanadium pentoxide film was created by using templating methods. The morphology, optical and electrochromic properties of the macro- and mesoporous films, prepared in the presence of structure-directing agents such as polystyrene microspheres and triblock copolymer, have been compared with those of dense films. By using various methods to remove the template material, it was shown that the morphology of the vanadium pentoxide film can be controlled and new nanostructures can be created. The transformation of the lamellar into a nanorod structure, observed when the film is heated at 425-500◦C for several hours, resulted in the development of an elegant method for the synthesis of vanadium oxide nanostructures. The electrochromic performance of the nanorods prepared through the thermal treatment was found to be superior to that of the vanadium pentoxide with the layered structure, especially in the near-infrared region, demonstrating their potential for electrochromic applications. The structure, morphology, optical and electrochromic properties of dense and porous vanadium oxide films, coated at low temperature were also determined and compared to those of the corresponding films, deposited under room-temperature conditions. The results indicated that in the films coated at -100C, a residual compressive stress exists that originates from a non-uniformity in depth of the film, most probably, due to the formation of micro voids during the deposition. The micro voids are preserved during the heat-treatment of the films. The "micro void" morphology was found to account for the considerably improved electrochromic properties of the sub-zero dip-coated films. Low-temperature coated films, heated at 4500C for several hours, undergo the transformation from a layered to a highly uniform nanorod structure with important potential optoelectronic applications. The overall aim of this work is thus to evaluate how the morphology of vanadium pentoxide thin films is instrumental in obtaining a material with a high lithium ion intercalation capacity. With an appropriate morphology, the performance of vanadium oxide as electrochromic material and as cathode in lithium ion batteries can be improved significantly. For this purpose, both layered (dense and porous) and nanorod films were prepared and characterized. Scanning electron microscopy, cyclic voltammetry and electrical impedance spectroscopy measurements were used for the characterization of the different V2O5 films.

Electrochromic Properties of Vanadium Pentoxide Nanostructured Thin Films

Electrochromic Properties of Vanadium Pentoxide Nanostructured Thin Films PDF Author: Afaf Almoabadi
Publisher:
ISBN:
Category :
Languages : en
Pages : 92

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Book Description
ABSTRACT Electrochromic Properties of Vanadium Pentoxide Nanostructured Thin Films Afaf Almoabadi The focus of this work is the improvement of the electrochromic properties of vanadium pentoxide thin films in order to expand its use. Indeed, because of its rather poor electrochromic properties, until now, vanadium pentoxide has only been used as a storage material in an electrochromic device, in conjunction with tungsten oxide, molybdenum oxide etc. To this purpose, vanadium pentoxide thin films were prepared under different conditions and characterized by using optical and electrochemical methods. Films were deposited on indium tin oxide (ITO) substrates by dip-coating at both room- and sub-zero temperature (-100C) and porosity in the sol-gel prepared vanadium pentoxide film was created by using templating methods. The morphology, optical and electrochromic properties of the macro- and mesoporous films, prepared in the presence of structure-directing agents such as polystyrene microspheres and triblock copolymer, have been compared with those of dense films. By using various methods to remove the template material, it was shown that the morphology of the vanadium pentoxide film can be controlled and new nanostructures can be created. The transformation of the lamellar into a nanorod structure, observed when the film is heated at 425-500◦C for several hours, resulted in the development of an elegant method for the synthesis of vanadium oxide nanostructures. The electrochromic performance of the nanorods prepared through the thermal treatment was found to be superior to that of the vanadium pentoxide with the layered structure, especially in the near-infrared region, demonstrating their potential for electrochromic applications. The structure, morphology, optical and electrochromic properties of dense and porous vanadium oxide films, coated at low temperature were also determined and compared to those of the corresponding films, deposited under room-temperature conditions. The results indicated that in the films coated at -100C, a residual compressive stress exists that originates from a non-uniformity in depth of the film, most probably, due to the formation of micro voids during the deposition. The micro voids are preserved during the heat-treatment of the films. The "micro void" morphology was found to account for the considerably improved electrochromic properties of the sub-zero dip-coated films. Low-temperature coated films, heated at 4500C for several hours, undergo the transformation from a layered to a highly uniform nanorod structure with important potential optoelectronic applications. The overall aim of this work is thus to evaluate how the morphology of vanadium pentoxide thin films is instrumental in obtaining a material with a high lithium ion intercalation capacity. With an appropriate morphology, the performance of vanadium oxide as electrochromic material and as cathode in lithium ion batteries can be improved significantly. For this purpose, both layered (dense and porous) and nanorod films were prepared and characterized. Scanning electron microscopy, cyclic voltammetry and electrical impedance spectroscopy measurements were used for the characterization of the different V2O5 films.

Nanostructured Thin Films

Nanostructured Thin Films PDF Author: Maria Benelmekki
Publisher: Elsevier
ISBN: 0081025734
Category : Technology & Engineering
Languages : en
Pages : 334

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Book Description
Nanostructured Thin Films: Fundamentals and Applications presents an overview of the synthesis and characterization of thin films and their nanocomposites. Both vapor phase and liquid phase approaches are discussed, along with the methods that are sufficiently attractive for large-scale production. Examples of applications in clean energy, sensors, biomedicine, anticorrosion and surface modification are also included. As the applications of thin films in nanomedicine, cell phones, solar cell-powered devices, and in the protection of structural materials continues to grow, this book presents an important research reference for anyone seeking an informed overview on their structure and applications. Shows how thin films are being used to create more efficient devices in the fields of medicine and energy harvesting Discusses how to alter the design of nanostructured thin films by vapor phase and liquid phase methods Explores how modifying the structure of thin films for specific applications enhances their performance

Electrochromic Materials and Devices

Electrochromic Materials and Devices PDF Author: Roger J. Mortimer
Publisher: John Wiley & Sons
ISBN: 352767988X
Category : Technology & Engineering
Languages : en
Pages : 672

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Book Description
Electrochromic materials can change their properties under the influence of an electrical voltage or current. Different classes of materials show this behavior such as transition metal oxides, conjugated polymers, metal-coordinated complexes and organic molecules. As the color change is persistent, the electric field needs only to be applied to initiate the switching, allowing for applications such as low-energy consumption displays, light-adapting mirrors in the automobile industry and smart windows for which the amount of transmitted light and heat can be controlled. The first part of this book describes the different classes and processing techniques of electrochromic materials. The second part highlights nanostructured electrochromic materials and device fabrication, and the third part focuses on the applications such as smart windows, adaptive camouflage, biomimicry, wearable displays and fashion. The last part rounds off the book by device case studies and environmental impact issues.

Multi-electrochromism of Vanadium Pentoxide Thin Films Using AFM Nanolithography

Multi-electrochromism of Vanadium Pentoxide Thin Films Using AFM Nanolithography PDF Author: Shiho Iwanaga
Publisher:
ISBN:
Category : Microlithography
Languages : en
Pages : 174

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Book Description


Nanostructured Electrochromic Materials for Smart Switchable Windows

Nanostructured Electrochromic Materials for Smart Switchable Windows PDF Author: Avinash Balakrishnan
Publisher: CRC Press
ISBN: 0429779607
Category : Technology & Engineering
Languages : en
Pages : 117

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Book Description
This book focuses on next-generation smart windows which can change their optical-physical properties by reflecting and/or transmitting incoming light radiation to attain comfortable indoor temperatures throughout the year. Offers in-depth discussion of a range of materials and devices related to different technologies used in manufacturing smart windows Discusses basic principles, materials synthesis and thin film fabrication, and optical and electrochemical characterization techniques

Electrochromic Materials and Devices

Electrochromic Materials and Devices PDF Author: Roger J. Mortimer
Publisher: John Wiley & Sons
ISBN: 3527336109
Category : Technology & Engineering
Languages : en
Pages : 668

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Book Description
Electrochromic materials can change their properties under the influence of an electrical voltage or current. Different classes of materials show this behavior such as transition metal oxides, conjugated polymers, metal-coordinated complexes and organic molecules. As the color change is persistent, the electric field needs only to be applied to initiate the switching, allowing for applications such as low-energy consumption displays, light-adapting mirrors in the automobile industry and smart windows for which the amount of transmitted light and heat can be controlled. The first part of this book describes the different classes and processing techniques of electrochromic materials. The second part highlights nanostructured electrochromic materials and device fabrication, and the third part focuses on the applications such as smart windows, adaptive camouflage, biomimicry, wearable displays and fashion. The last part rounds off the book by device case studies and environmental impact issues.

Transition Metal Oxide Thin Film-Based Chromogenics and Devices

Transition Metal Oxide Thin Film-Based Chromogenics and Devices PDF Author: Pandurang Ashrit
Publisher: Elsevier
ISBN: 0081017480
Category : Technology & Engineering
Languages : en
Pages : 378

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Book Description
The phase transition and the reversible optical and electrical switching that occur in chromogenic materials under the influence of external forces such as heat, light, and electric field are topics of enormous scientific interest. Transition Metal Oxide Thin Film–Based Chromogenics and Devices discusses experimental and theoretical developments in the field of chromogenics based on the transition metal oxide (TMO) thin films. Understanding the relationship between the switching properties of TMO materials and their nanostructure is of paramount importance in developing efficient chromogenic devices. The tailoring of these switching behaviors is afforded detailed coverage in this book, alongside in-depth discussion of a range of chromogenic materials and devices, including photochromics, thermochromics, and electrochromics. Transition Metal Oxide Thin Film–Based Chromogenics and Devices covers both the theoretical aspects of TMO thin film–based chromogenics and their engineering applications in device construction. Academics and professionals in the fields of materials science and optics will find this book to be a key resource, whether their focus is low-dimension materials, light-materials interactions, or device development. - Enables researchers to keep up with developments in thin film–based chromogenics - Provides detailed coverage of the switching mechanism of the various TMO thin films to assist readers in developing more efficient devices - Offers in-depth discussion of a range of chromogenic materials and devices, including thermochromics, photochromics, and electrochromics

Current Research in Pulsed Laser Deposition

Current Research in Pulsed Laser Deposition PDF Author: Liviu Duta
Publisher: MDPI
ISBN: 3036510443
Category : Medical
Languages : en
Pages : 224

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Book Description
Despite its limitation in terms of surface covered area, the PLD technique still gathers interest among researchers by offering endless possibilities for tuning thin film composition and enhancing their properties of interest due to: (i) the easiness of a stoichiometric transfer even for very complex target materials, (ii) high adherence of the deposited structures to the substrate, (iii) controlled degree of phase, crystallinity, and thickness of deposited coatings, (iv) versatility of the experimental set-up which allows for simultaneous ablation of multiple targets resulting in combinatorial maps or consecutive ablation of multiple targets producing multi-layered structures, and (v) adjustment of the number of laser pulses, resulting in either a spread of nanoparticles, islands of materials or a complete covering of a surface. Moreover, a variation of PLD, known as Matrix Assisted Pulsed Laser Evaporation, allows for deposition of organic materials, ranging from polymers to proteins and even living cells, otherwise difficult to transfer unaltered in the form of thin films by other techniques. Furthermore, the use of laser light as transfer agent ensures purity of films and pulse-to-pulse deposition allows for an unprecedented control of film thickness at the nm level. This Special Issue is a collection of state-of-the art research papers and reviews in which the topics of interest are devoted to thin film synthesis by PLD and MAPLE, for numerous research and industry field applications, such as bio-active coatings for medical implants and hard, protective coatings for cutting and drilling tools withstanding high friction and elevated temperatures, sensors, solar cells, lithography, magnetic devices, energy-storage and conversion devices, controlled drug delivery and in situ microstructuring for boosting of surface properties.

Microbolometers

Microbolometers PDF Author: Nuggehalli Ravindra
Publisher: Woodhead Publishing
ISBN: 008102813X
Category : Technology & Engineering
Languages : en
Pages : 352

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Book Description
Microbolometers: Fundamentals, Materials, and Recent Developments describes the fundamentals of microbolometers, their historic evolution, operational principles and material choices. It also explains the impact of materials on the processing and development of device characteristics. Sections address various aspects of optical properties and recommend models of properties of materials of interest for the fabrication of the uncooled microbolometers. In addition, the book presents two case studies, Honeywell and Texas Instruments, that focus on the design and manufacture of microbolometers. Finally, recent developments, applications, patents and future trends are presented. The chapter on patents will summarize the strengths and weaknesses of each of the technologies. "Please note that there is an error on the Dedication page, it should read: "To my sister, Math. G.Y. Premalatha, and my brother-in-law, the late Professor G.N. Yoganarasimhan, Professor of Water Resources Engineering and Management, for showing me the direction - Describes the fundamentals of uncooled infrared detectors, operational principles and material approaches - Includes case studies based on Honeywell and Texas Instruments' work on microbolometers - Provides analyses of current patents with a look towards their strengths and weaknesses

Electrochromism and Electrochromic Devices

Electrochromism and Electrochromic Devices PDF Author: Paul Monk
Publisher: Cambridge University Press
ISBN: 1139465562
Category : Technology & Engineering
Languages : en
Pages :

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Book Description
Electrochromic materials, both organic and inorganic, have widespread applications in light-attenuation, displays and analysis. Written in an accessible manner, this book provides a comprehensive treatment of all types of electrochromic systems and their many applications. Coverage develops from electrochromic scope and history to new searching presentations of optical quantification and theoretical mechanistic models. Non-electrode electrochromism and photo-electrochromism are summarised, with updated comprehensive reviews of electrochromic oxides (tungsten-trioxide particularly), metal co-ordination complexes and metal-cyanometallates, viologens and other organics; and more recent exotics such as fullerenes, hydrides, and conjugated electroactive polymers are also covered. The book concludes by examining device construction and durability. With an extensive bibliography, recent advances in the field, modern applications and a step-by-step development from simple examples to sophisticated theories, this book is ideal for researchers in materials science, polymer science, electrical engineering, physics, chemistry, bioscience and (applied) optoelectronics.