Download or read book Hydrothermal Synthesis of Al doped ZnO Nanowires and Their Application for Photovoltaic Devices written by Hyoungwon Park and published by . This book was released on 2014 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiconductor nanostructures exhibit distinct properties by virtue of nano-scale dimensionality, resulting in recent interest in semiconducting nanowires for electronic, photonic, and energy applications. Along with nanowires, quantum dots are solution-processable nanocrystals with tunable band gap energies as a function of their size. Based on all of these promising properties that nanostructures exhibit, nanowires and quantum dots are excellent candidates for next-generation optoelectronic devices, including solar cells and light-emitting diodes. However, the realization of nanostructured materials for solar cell device applications is limited by the fundamental trade-off between light absorption and photocarrier collection. Vertically aligned ZnO nanowire arrays can decouple absorption and collection by acting as highly-conductive channels for extracting photogenerated electrons from deep within the film. This thesis illustrates a scheme for the development of ordered bulk heterojunction photovoltaic devices incorporating solution-based n-type doped ZnO nanowires and PbS quantum dots. In order to improve the electrical properties of ZnO nanowires, Al doping of hydrothermally synthesized ZnO nanowires is studied along with the optimization of doping concentration. The morphology of ZnO nanowire arrays is also studied as a function of the doping concentration in the growth solution. Finally, photovoltaic devices are fabricated and the effect of Al-doping of ZnO nanowires is investigated by device characterization techniques.

Download or read book Hydrothermal Synthesis of Zinc Oxide Nanowire Arrays for Photovoltaic Applications written by Jian Wei Jayce Cheng and published by . This book was released on 2016 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt: Zinc oxide (ZnO) nanowires with excellent crystal quality can be grown vertically aligned from a substrate using hydrothermal synthesis, a low-cost, scalable process that is compatible with many semiconductor processing techniques. However, precise control over nanowire array dimensions such as nanowire spacing, diameter, length, and alignment, which is important for optoelectronic device applications, has proven elusive due to lack of understanding regarding fundamental aqueous growth mechanisms at the nanoscale. Here, we utilize electron-beam lithography to template ZnO seed layers, demonstrating that seed layer engineering via judicious choice of seed deposition conditions and annealing can yield well-aligned nanowire arrays with single nanowire spatial precision on a variety of device relevant substrates. Subsequently, we use bottom-up patterning techniques and investigate the competition between diffusive transport and surface reaction in hydrothermal growth to achieve control over nanowire spacing and enhanced nanowire array uniformity over length scales suitable for photovoltaic (PV) device fabrication. By analyzing the role of temperature, concentration, and areal seed density on the balance between diffusion vs. reaction rates at the solution-nanowire interface, we show that the c-facet grows via the direct incorporation mechanism. With this knowledge, we use additives to shift the nanowire growth system into a reaction-limited regime, making nanowire growth rate independent of the patterned template. As a consequence, we achieve ZnO nanowire array uniformity that is critical for device applications.

Download or read book Toward the Optimization of Low temperature Solution based Synthesis of ZnO Nanostructures for Device Applications written by Hatim Alnoor and published by Linköping University Electronic Press. This book was released on 2017-10-06 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: One-dimensional (1D) nanostructures (NSs) of Zinc Oxide (ZnO) such as nanorods (NRs) have recently attracted considerable research attention due to their potential for the development of optoelectronic devices such as ultraviolet (UV) photodetectors and light-emitting diodes (LEDs). The potential of ZnO NRs in all these applications, however, would require synthesis of high crystal quality ZnO NRs with precise control over the optical and electronic properties. It is known that the optical and electronic properties of ZnO NRs are mostly influenced by the presence of native (intrinsic) and impurities (extrinsic) defects. Therefore, understanding the nature of these intrinsic and extrinsic defects and their spatial distribution is critical for optimizing the optical and electronic properties of ZnO NRs. However, identifying the origin of such defects is a complicated matter, especially for NSs, where the information on anisotropy is usually lost due to the lack of coherent orientation. Thus, the aim of this thesis is towards the optimization of the lowtemperature solution-based synthesis of ZnO NRs for device applications. In this connection, we first started with investigating the effect of the precursor solution stirring durations on the deep level defects concentration and their spatial distribution along the ZnO NRs. Then, by choosing the optimal stirring time, we studied the influence of ZnO seeding layer precursor’s types, and its molar ratios on the density of interface defects. The findings of these investigations were used to demonstrate ZnO NRs-based heterojunction LEDs. The ability to tune the point defects along the NRs enabled us further to incorporate cobalt (Co) ions into the ZnO NRs crystal lattice, where these ions could occupy the vacancies or interstitial defects through substitutional or interstitial doping. Following this, high crystal quality vertically welloriented ZnO NRs have been demonstrated by incorporating a small amount of Co into the ZnO crystal lattice. Finally, the influence of Co ions incorporation on the reduction of core-defects (CDs) in ZnO NRs was systematically examined using electron paramagnetic resonance (EPR).

Download or read book Facile Synthesis and Characterization of Al Doped ZnO Nanostructures and Their Applications in Sensors and Solar Cells written by 唐健富 and published by . This book was released on 2017 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nanowires written by Felix Ryler and published by . This book was released on 2016-10-01 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: The properties of nanowires have caused researchers and companies to consider using this material in several fields. Nanowires are nanostructures that have a thickness or diameter constrained to tens of nanometers or less and an unconstrained length. In addition, many different types of nanowires exist, including metallic, semiconducting and insulating. Nanowires hold lot of promises for different applications. Basic electronic devices like junction diodes, transistors, FETs and logic gates can be fabricated by using semiconductor and superlattice nanowires. Thermoelectric cooling system can be fabricated by using metallic nanowires. Semiconductor nanowire junctions can be used for different optoelectronic applications. Moreover, periodic arrays of magnetic nanowires hold high potential for recording media application. Nanowires are also potential candidates for sensor and bio-medical applications. Depending on what it's made from, a nanowire can have the properties of an insulator, a semiconductor or a metal.Nanowires - Implementations and Applications presents current research in the study of the properties, synthesis and application of nanowires. Topics discussed include semiconductor nanowires and heterostructure based gas sensors; transport properties of nanostructured materials; nanowire array electrodes in biosensor applications and analogies between metallic nanowires and carbon nanotubes.

Download or read book Synthesis and Characterization of ZnO Graphene Nanostructures for Electronics and Photocatalysis written by Seyed Ebrahim Chalangar and published by Linköping University Electronic Press. This book was released on 2021-04-08 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent rapid development of electronics and electro-optical devices demands affordable and reliable materials with enhanced performance. Forming nanocomposites of already well-known materials is one possible route towards novel functional materials with desirable synergistic enhanced properties. Incompatible chemical properties, mismatched crystal structures and weak bonding interactions between the substances, however, often limit the number of possible nanocomposites. Moreover, using an inexpensive, facile, large-area and flexible fabrication technique is crucial to employ the new composites in industrially viable applications. This thesis focuses on the synthesis and characterization of different zinc oxide/graphene (ZnO/GR) nanocomposites, well suited for optoelectronics and photocatalysis applications. Two different approaches of i) substrate-free random synthesis, and ii) template-assisted selective area synthesis were studied in detail. In the first approach, ZnO nanoparticles/rods were grown on GR. The obtained nanocomposites were investigated for better GR dispersity, electrical conductivity and optical properties. Besides, by adding silver iodide to the nanocomposite, an enhanced plasmonic solar-driven photocatalyst was synthesized and analyzed. In the second approach, arrays of single, vertically aligned ZnO nanorods were synthesized using a colloidal lithography-patterned sol-gel ZnO seed layer. Our demonstrated nanofabrication technique with simple, substrate independent, and large wafer-scale area compatibility improved the alignment and surface density of ZnO nanorods over large selective growth areas. Eventually, we found a novel method to further enhance the vertical alignment of the ZnO nanorods by introducing a GR buffer layer between the Si substrate and the ZnO seed layer, together with the mentioned patterning technique. The synthesized nanocomposites were analyzed using a large variety of experimental techniques including electron microscopy, photoelectron spectroscopy, x-ray diffraction, photoluminescence and cathodoluminescence spectroscopy for in-depth studies of their morphology, chemical and optical properties. Our findings show that the designed ZnO/GR nanocomposites with vertically aligned ZnO nanorods of high crystalline quality, synthesized with the developed low-cost nanofabrication technique, can lead to novel devices offering higher performance at a significantly lower fabrication cost.

Download or read book Zinc Oxide written by Hadis Morkoç and published by John Wiley & Sons. This book was released on 2008-12-03 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: This first systematic, authoritative and thorough treatment in one comprehensive volume presents the fundamentals and technologies of the topic, elucidating all aspects of ZnO materials and devices. Following an introduction, the authors look at the general properties of ZnO, as well as its growth, optical processes, doping and ZnO-based dilute magnetic semiconductors. Concluding sections treat bandgap engineering, processing and ZnO nanostructures and nanodevices. Of interest to device engineers, physicists, and semiconductor and solid state scientists in general.

Download or read book Handbook of Emerging Materials for Sustainable Energy written by Naveen V. Kulkarni and published by Elsevier. This book was released on 2024-02-28 with total page 1034 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handbook of Emerging Materials for Sustainable Energy provides a comprehensive accounting on the fundamentals, current developments, challenges and future prospects of emerging materials for the development of sustainable energy. Each chapter addresses a distinct and important area within the energy field and includes comprehensive data to support the materials being presented. Sections cover Batteries, Capacitors and Supercapacitors, Fuel cells, Thermoelectrics, Novel illumination sources and techniques, Photovoltaics & Solar cells, Alternative energy sources, hydrogen as an energy source, including hydrogen production and fuel generation, the use of Biofuels and Carbon dioxide. The book concludes with three chapters related to advanced materials under development for energy conservation and environmental protection, including theories, methodologies and simulations established for advanced materials. - Covers a broad scope of advanced materials that have been developed for energy and environmental sustainability - Provides detailed and updated information about the structural and functional features of various emerging materials and their multifaceted applications - Includes supplementary data alongside each chapter

Download or read book Synthesis and Characterization of Zinc Oxide Nanowires and Their Use in Spintronic and Photovoltaic Applications written by Benjamin Daniel Yuhas and published by . This book was released on 2009 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nanophotocatalysis and Environmental Applications written by Inamuddin and published by Springer. This book was released on 2019-03-14 with total page 343 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book serves the environmentalists to track the development of photocatalytic materials and technology in the present context and to explore future trends. Photocatalysis is the most influential greener technology being researched, developed and adopted for the treatment of wastewater. The technological advancements in the area of smart hybrid photocatalytic materials have gained momentum in the present era. The rational designing of photocatalytic materials with a multi-pronged approach opens a new chapter for environmental detoxification. Other important aspects relate to the transfer of this nanostructured photocatalytic technology to real backdrops. Harnessing natural solar energy for energy and environmental roles is another crucial criterion in designing photocatalysts.

Download or read book Properties of Al Doped ZnO Nanorods Synthesized Using Low Temperature Hydrothermal Method written by and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ZnO Nanostructure Synthesis Laser Direct Writing Process for Optoelectronic Devices written by DAEHO LEE and published by . This book was released on 2012 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: Zinc oxide (ZnO) has a long history of usage in electronics. Recently, ZnO has been gathering great interest of researchers in nanoscience due to its diverse and versatile morphologies such as nanoparticles (NP), nanowires (NW), nanorods, nanotubes, nanohelixes, etc. This dissertation deals with studies covering from the synthesis of ZnO nanostructures to deposition & patterning methods and their applications for optoelectronic devices such as transparent electrodes, active layers for thin film transistor and photovoltaics. A very well-dispersed, transparent and concentration-tunable ZnO NP solution was successfully synthesized with a new process. Highly transparent ZnO thin films were fabricated by spin coating and subsequent ultra short-pulsed UV laser annealing was performed to change the film properties. While as-deposited NP thin films were not electrically conductive, laser annealing imparted a substantial conductivity increase. Thus, selective annealing for conductive patterns directly on the NP thin film without a photolithographic process was achieved. The conductivity is by a factor of 105 higher than that of the previously reported furnace-annealed ZnO NP films and even comparable to that of vacuum-deposited, impurity-doped ZnO films within a factor of 10. The ZnO film obtained from the process developed in this work has been applied to the fabrication of a thin film transistor (TFT) showing enhanced performance compared with the TFT fabricated on furnace annealed ZnO film. The ZnO TFT performance test reveals that by just changing the laser annealing parameters the solution-deposited ZnO thin film properties can be tuned suitable for both transparent conductors and semiconductor active layers. Two kinds of nanomaterial patterning methods via direct writing have been demonstrated. First, laser-assisted nanoimprinting of metal and semiconductor nanoparticles has been presented as a large area one step patterning method. With the method, submicron structures including mesh, line, nanopillar and nanowire arrays were fabricated on various kinds of wafer scale substrates. Using the rapid laser-based nanolithography, the prohibitive constraints of e-beam patterning could be overcome. Therefore, this method opens a way to the fabrication of electronic and energy devices with high throughput and ultra low-cost. Second, a drop on demand (DOD) inkjet printing of ZnO seed layers integrated with a CAD (computer aided design) system for a fully digital selective ZnO NW array growth has been discussed. Through proper natural convection suppression during the hydrothermal growth, successful ZnO nanowire local growth could be achieved. Without any need for the photolithographic process or stamp preparation, the NW growth location can be easily modified with high degree of freedom. These two methods are compatible with flexible plastic substrates. As an application of ZnO nanostructures for high efficiency solar cells, ZnO dye-sensitized solar cells (DSSCs) with greatly enhanced surface area for higher dye loading and light harvesting were demonstrated. The selective growth of "nanoforests" composed of high density, long branched tree-like multi generation hierarchical ZnO nanowire photoanodes by utilizing seed particles and a capping polymer increased the energy conversion efficiency significantly. The overall light-conversion efficiency of the branched ZnO nanowire DSSCs was almost 5 times higher than the efficiency of DSSCs constructed by upstanding ZnO nanowires. A parametric study to determine the optimum hierarchical ZnO nanowire photoanode was performed through the combination of both length-wise and branched growth processes.

Download or read book Zinc Oxide Based Nano Materials and Devices written by , Prof. Dr. Ahmed Nahhas and published by BoD – Books on Demand. This book was released on 2019-10-09 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a review of recent advances in ZnO-based nanomaterials and devices. ZnO as a nanomaterial has gained substantial interest in the research area of wide bandgap semiconductors and is considered to be one of the major candidates for electronic and photonic applications. ZnO has distinguished and interesting electrical and optical properties and is considered to be a potential material in optoelectronic applications such as solar cells, surface acoustic wave devices, and UV emitters. ZnO's unique properties have attracted several researchers to study its electrical and optical properties. As a nanostructured material, ZnO exhibits many advantages for nanodevices. Moreover, it has the ability to absorb the UV radiation.

Download or read book Zinc Oxide Nanostructures written by Magnus Willander and published by CRC Press. This book was released on 2014-07-22 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: Zinc oxide (ZnO) in its nanostructured form is emerging as a promising material with great potential for the development of many smart electronic devices. This book presents up-to-date information about various synthesis methods to obtain device-quality ZnO nanostructures. It describes both high-temperature (over 100 C) and low-temperature (under

Download or read book System Materials Nanoarchitectonics written by Yutaka Wakayama and published by Springer Nature. This book was released on 2022-01-03 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is the first publication to widely introduce the contributions of nanoarchitectonics to the development of functional materials and systems. The book opens up pathways to novel nanotechnology based on bottom-up techniques. In fields of nanotechnology, theoretical and practical limitations are expected in the bottom-up nanofabrication process. Instead, some supramolecular processes for nano- and microstructure formation including molecular recognition, self-assembly, and template synthesis have gained great attention as novel key technologies to break through expected limitations in current nanotechnology. This volume describes future images of nanotechnology and related materials and device science as well as practical applications for energy and biotechnology. Readers including specialists, non-specialists, graduate students, and undergraduate students can focus on the parts of the book that interest and concern them most. Target fields include materials chemistry, organic chemistry, physical chemistry, nanotechnology, and even biotechnology.

Download or read book Comprehensive Energy Systems written by Ibrahim Dincer and published by Elsevier. This book was released on 2018-02-07 with total page 5543 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive Energy Systems, Seven Volume Set provides a unified source of information covering the entire spectrum of energy, one of the most significant issues humanity has to face. This comprehensive book describes traditional and novel energy systems, from single generation to multi-generation, also covering theory and applications. In addition, it also presents high-level coverage on energy policies, strategies, environmental impacts and sustainable development. No other published work covers such breadth of topics in similar depth. High-level sections include Energy Fundamentals, Energy Materials, Energy Production, Energy Conversion, and Energy Management. Offers the most comprehensive resource available on the topic of energy systems Presents an authoritative resource authored and edited by leading experts in the field Consolidates information currently scattered in publications from different research fields (engineering as well as physics, chemistry, environmental sciences and economics), thus ensuring a common standard and language

Download or read book Nanowires written by Nicoleta Lupu and published by BoD – Books on Demand. This book was released on 2010-02-01 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes nanowires fabrication and their potential applications, both as standing alone or complementing carbon nanotubes and polymers. Understanding the design and working principles of nanowires described here, requires a multidisciplinary background of physics, chemistry, materials science, electrical and optoelectronics engineering, bioengineering, etc. This book is organized in eighteen chapters. In the first chapters, some considerations concerning the preparation of metallic and semiconductor nanowires are presented. Then, combinations of nanowires and carbon nanotubes are described and their properties connected with possible applications. After that, some polymer nanowires single or complementing metallic nanowires are reported. A new family of nanowires, the photoferroelectric ones, is presented in connection with their possible applications in non-volatile memory devices. Finally, some applications of nanowires in Magnetic Resonance Imaging, photoluminescence, light sensing and field-effect transistors are described. The book offers new insights, solutions and ideas for the design of efficient nanowires and applications. While not pretending to be comprehensive, its wide coverage might be appropriate not only for researchers but also for experienced technical professionals.