Download or read book Fabrication of Vertical Silicon Nanowires Through Metal Assisted Deposition written by Matthew Garett Young and published by . This book was released on 2012 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: Controlled and ordered growth of Si nanowires through a low temperature fabrication method compatible with CMOS processing lines is a highly desirable replacement to future electronic fabrication technologies as well as a candidate for a low cost route to inexpensive photovoltaics. This stems from the fact that traditional CMOS based electronics are hitting physical barriers that are slowing the Moore's Law trend as well as the demand for an inexpensive solar cell technology that can obtain grid parity. A fractional factorial growth study is presented that compares the growth of Au and Al catalyzed Si nanowires at temperatures ranging from 150 to 400° C. Dense and prolific growth of Si nanowires on 111 and 100 Si substrates as well as glass substrates was obtained using a Au catalyst at temperatures of 400° C. An overview is given that considers all growth experiments and includes TEM analysis of individual Si nanowires grown on Si substrates showing nanowires to be both crystalline and amorphous in nature. Optical transmission data of bulk Si nanowire films on glass substrates showed that the collective optical properties were highly desirable as transmission was minimized over the 300 to 1400 nm wavelength range at different transmission angles. Collectively, a growth platform is presented from which further material study will yield advanced Si nanowire based devices, satisfying a demand by the ITRS and the scientific community at large for electronics that can continue the Moore's law trend and inexpensive photovoltaics capable of meeting the consumer demand for grid parity.

Download or read book Fabrication of High Aspect Ratio Silicon Nanostructure Arrays by Metal assisted Etching written by Shih-wei Chang (Ph.D.) and published by . This book was released on 2010 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this research was to explore and understand the mechanisms involved in the fabrication of silicon nanostructures using metal-assisted etching. We developed a method utilizing metal-assisted etching in conjunction with block copolymer lithography to create ordered and densely-packed arrays of high-aspect-ratio single-crystal silicon nanowires with uniform crystallographic orientations. Nanowires with sub-20 nm diameters were created as either continuous carpets or as carpets within trenches. Wires with aspect ratios up to 220 with much reduced capillary-induced clustering were achieved through post-etching critical point drying. The size distribution of the diameters was narrow and closely followed the size distribution of the block copolymer. Fabrication of wires in topographic features demonstrated the ability to accurately control wire placement. The flexibility of this method will facilitate the use of such wire arrays in micro- and nano-systems in which high device densities and/or high surface areas are desired. In addition, we report a systematic study of metal-catalyzed etching of (100), (110), and (111) silicon substrates using gold catalysts with varying geometrical characteristics. It is shown that for isolated catalyst nanoparticles and metal meshes with small hole spacings, etching proceeded preferentially in the 100 direction. However, etching was confined in the direction vertical to the substrate surface when a catalyst mesh with large hole spacings was used. This result was used to demonstrate the use of metal-assisted etching to create arrays of vertically-aligned polycrystalline and amorphous silicon nanowires etched from deposited silicon thin films using catalyst meshes with relatively large hole spacings. The ability to pattern wires from polycrystalline and amorphous silicon thin films opens the possibility of making silicon nanowire-array-based devices on a much wider range of substrates. Finally, we demonstrated the fabrication of a silicon-nanopillar-based nanocapacitor array using metal-assisted etching and electrodeposition. The capacitance density was increased significantly as a result of an increased electrode area made possible by the catalytic etching approach. We also showed that the measured capacitance densities closely follow the expected trend as a function of pillar height and array period. The capacitance densities can be further enhanced by increasing the array density and wire length with the incorporation of known self-assembly-based patterning techniques such as block copolymer lithography.

Download or read book Handbook of Porous Silicon written by Leigh Canham and published by Springer. This book was released on 2021-01-14 with total page 1000 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Handbook of Porous Silicon brings together the expertise of a large, international team of almost 100 academic researchers, engineers, and product developers from industry across electronics, medicine, nutrition and consumer care to summarize the field in its entirity with 150 chapters and 5000 references. The volume presents 5 parts which cover fabrication techniques, material properties, characterization techniques, processing and applications. Much attention was given in the the past to its luminescent properties, but increasingly it is the biodegradability, mechanical, thermal and sensing capabilities that are attracting attention. The volume is divided into focussed data reviews with, wherever possible, quantitative rather than qualitative descriptions of both properties and performance. The book is targeted at undergraduates, postgraduates, and experienced researchers.

Download or read book Micro and Nano Fabrication by Metal Assisted Chemical Etching written by Lucia Romano and published by MDPI. This book was released on 2021-01-13 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal-assisted chemical etching (MacEtch) has recently emerged as a new etching technique capable of fabricating high aspect ratio nano- and microstructures in a few semiconductors substrates—Si, Ge, poly-Si, GaAs, and SiC—and using different catalysts—Ag, Au, Pt, Pd, Cu, Ni, and Rh. Several shapes have been demonstrated with a high anisotropy and feature size in the nanoscale—nanoporous films, nanowires, 3D objects, and trenches, which are useful components of photonic devices, microfluidic devices, bio-medical devices, batteries, Vias, MEMS, X-ray optics, etc. With no limitations of large-areas and low-cost processing, MacEtch can open up new opportunities for several applications where high precision nano- and microfabrication is required. This can make semiconductor manufacturing more accessible to researchers in various fields, and accelerate innovation in electronics, bio-medical engineering, energy, and photonics. Accordingly, this Special Issue seeks to showcase research papers, short communications, and review articles that focus on novel methodological developments in MacEtch, and its use for various applications.

Download or read book Silicon Nanomaterials Sourcebook written by Klaus D. Sattler and published by CRC Press. This book was released on 2017-07-28 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive tutorial guide to silicon nanomaterials spans from fundamental properties, growth mechanisms, and processing of nanosilicon to electronic device, energy conversion and storage, biomedical, and environmental applications. It also presents core knowledge with basic mathematical equations, tables, and graphs in order to provide the reader with the tools necessary to understand the latest technology developments. From low-dimensional structures, quantum dots, and nanowires to hybrid materials, arrays, networks, and biomedical applications, this Sourcebook is a complete resource for anyone working with this materials: Covers fundamental concepts, properties, methods, and practical applications. Focuses on one important type of silicon nanomaterial in every chapter. Discusses formation, properties, and applications for each material. Written in a tutorial style with basic equations and fundamentals included in an extended introduction. Highlights materials that show exceptional properties as well as strong prospects for future applications. Klaus D. Sattler is professor physics at the University of Hawaii, Honolulu, having earned his PhD at the Swiss Federal Institute of Technology (ETH) in Zurich. He was honored with the Walter Schottky Prize from the German Physical Society, and is the editor of the sister work also published by Taylor & Francis, Carbon Nanomaterials Sourcebook, as well as the acclaimed multi-volume Handbook of Nanophysics.

Download or read book LIGA and its Applications written by Volker Saile and published by John Wiley & Sons. This book was released on 2009-01-07 with total page 491 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covering technological aspects as well as the suitability and applicability of various kinds of uses, this handbook shows optimization strategies, techniques and assembly pathways to achieve the combination of complex, even three-dimensional structures with simple manufacturing steps. The authors provide information on markets, commercialization opportunities and aspects of mass or large-scale production as well as design tools, experimental techniques, novel materials, and ideas for future improvements. Not only do they weigh up cost versus quantity, they also consider CMOS and LIGA strategies. Of interest to physicists, electronics engineers, materials scientists, institutional and industrial libraries as well as graduate students of the relevant disciplines.

Download or read book Fabrication and Characterization of Vertical Silicon Nanowire Arrays written by Jeffrey M. Weisse and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermoelectric devices, which convert temperature gradients into electricity, have the potential to harness waste heat to improve overall energy efficiency. However, current thermoelectric devices are not cost-effective for most applications due to their low efficiencies and high material costs. To improve the overall conversion efficiency, thermoelectric materials should possess material properties that closely resemble a "phonon glass" and an "electron crystal". The desired low thermal and high electrical conductivities allow the thermoelectric device to maintain a high temperature gradient while effectively transporting current. Unfortunately, thermal transport and electrical transport are a closely coupled phenomena and it is difficult to independently engineer each specific conduction mechanism in conventional materials. One strategy to realize this is to generate nanostructured silicon (e.g. silicon nanowires (SiNWs)), which have been shown to reduce thermal conductivity ([kappa]) through enhanced phonon scattering while theoretically preserving the electronic properties; therefore, improving the overall device efficiency. The ability to suppress phonon propagation in nanostructured silicon, which has a bulk phonon mean free path ~ 300 nm at 300 K, has raised substantial interest as an ultra-low [kappa] material capable of reducing the thermal conductivity up to three orders of magnitude lower than that of bulk silicon. While the formation of porous silicon and SiNWs has individually been demonstrated as promising methods to reduce [kappa], there is a lack of research investigating the thermal conductivity in SiNWs containing porosity. We fabricated SiNW arrays using top-down etching methods (deep reactive ion etching and metal-assisted chemical etching) and by tuning the diameter with different patterning methods and tuning the internal porosity with different SiNW etching conditions. The effects of both the porosity and the SiNW dimensions at the array scale are investigated by measuring [kappa] of vertical SiNW arrays using a nanosecond time-domain thermoreflectance technique. In addition to thermoelectric devices, vertical SiNW arrays, due to their anisotropic electronic and optical properties, large surface to volume ratios, resistance to Li-ion pulverization, ability to orthogonalize light absorption and carrier transport directions, and trap light, make vertical SiNW arrays important building blocks for various applications. These may include sensors, solar cells, and Li-ion batteries. Many of these applications benefit from vertical SiNW arrays fabricated on non-silicon based substrates which endow the final devices with the properties of flexibility, transparency, and light-weight while removing any performance limitation of the silicon fabrication substrate. We then developed two vertical transfer printing methods (V-TPMs) that are used to detach SiNW arrays from their original fabrication substrates and subsequently attach them to any desired substrate while retaining their vertical alignment over a large area. The transfer of vertically aligned arrays of uniform length SiNWs is desirable to remove the electrical, thermal, optical, and structural impact from the fabrication substrate and also to enable the integration of vertical SiNWs directly into flexible and conductive substrates. Moreover, realization of a thermoelectric device requires the formation of electrical contacts on both sides of the SiNW arrays. We formed metallic contacts on both ends of the SiNW arrays with a mechanical supporting and electrical insulating polymer in between. Electrical characterization of the SiNW devices exhibited good current-voltage (I-V) characteristics independent of substrates materials and bending conditions. We believe the V-TPMs developed in this work have great potential for manufacturing practical thermoelectric devices as well as high performing, scalable SiNW array devices on flexible and conducting substrates.

Download or read book Electrochemically Engineered Nanoporous Materials written by Dusan Losic and published by Springer. This book was released on 2015-07-18 with total page 377 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides in-depth knowledge about the fabrications, structures, properties and applications of three outstanding electrochemically engineered nanoporous materials including porous silicon, nanoporous alumina and nanotubular titania. The book integrates three major themes describing these materials. The first theme is on porous silicon reviewing the methods for preparation by electrochemical etching, properties and methods for surface functionalization relevant for biosensing applications. Biomedical applications of porous silicon are major focus, described in several chapters reviewing recent developments on bioanalysis, emerging capture probes and drug delivery. The second theme on nanoporous alumina starts with describing the concept of self-organized electrochemical process used for synthesis nanopore and nanotube structures of valve metal oxides and reviewing recent development and progress on this field. The following chapters are focused mainly on optical properties and biosensing application of nanoporous alumina providing the reader with the depth of understanding of the structure controlled optical and photonic properties and design of optical biosensing devices using different detection principles such as photoluminescence, surface plasmon resonance, reflective spectrometry, wave guiding, Raman scattering etc. The third theme is focused on nanotubular titania reviewing three key applications including photocatalysis, solar cells and drug delivery. The book represents an important resource for academics, researchers, industry professionals, post-graduate and high-level undergraduate students providing them with both an overview of the current state-of-the-art on these materials and their future developments.

Download or read book Semiconducting Silicon Nanowires for Biomedical Applications written by Jeffery L. Coffer and published by Woodhead Publishing. This book was released on 2021-09-14 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt: In its second, extensively revised second edition, Semiconducting Silicon Nanowires for Biomedical Applications reviews the fabrication, properties, and biomedical applications of this key material. The book begins by reviewing the basics of growth, characterization, biocompatibility, and surface modification of semiconducting silicon nanowires. Attention then turns to use of these structures for tissue engineering and delivery applications, followed by detection and sensing. Reflecting the evolution of this multidisciplinary subject, several new key topics are highlighted, including our understanding of the cell-nanowire interface, latest advances in associated morphologies (including silicon nanoneedles and nanotubes for therapeutic delivery), and significantly, the status of silicon nanowire commercialization in biotechnology. Semiconducting Silicon Nanowires for Biomedical Applications is a comprehensive resource for biomaterials scientists who are focused on biosensors, drug delivery, and the next generation of nano-biotech platforms that require a detailed understanding of the cell-nanowire interface, along with researchers and developers in industry and academia who are concerned with nanoscale biomaterials, in particular electronically-responsive structures. - Reviews the growth, characterization, biocompatibility, and surface modification of semiconducting silicon nanowires - Describes silicon nanowires for tissue engineering and delivery applications, including cellular binding & internalization, tissue engineering scaffolds, mediated differentiation of stem cells, and silicon nanoneedles & nanotubes for delivery of small molecule / biologic-based therapeutics - Highlights the use of silicon nanowires for detection and sensing - Presents a detailed description of our current understanding of the cell-nanowire interface - Covers the current status of commercial development of silicon nanowire-based platforms

Download or read book Effect of Thermal Oxide Film on Scalable Fabrication of Silicon Nanowire Arrays Using Metal Assisted Chemical Etching written by Mariana Castaneda and published by . This book was released on 2020 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last several decades, the demand for real-time data processing and storage has exponentially increased and pushed the semiconductor field to its fabrication limits. Traditional methods of semiconductor nanomanufacturing, like lithography and reactive ion etching (RIE), suffer from feature resolution and etch taper limits for devices comprising sub-10 nm nanofabrication nodes. Methods like the ones mentioned above are both expensive and difficult to manufacture to keep up with continued scaling requirements of semiconductor fabrication. This thesis presents a fabrication method and metrology characterization of silicon nanowire arrays using a Metal Assisted Chemical Etching (MACE) approach. MACE is a simple, low-cost fabrication technique that allows for high aspect ratio silicon nanostructures to be successfully fabricated without sacrificing geometry fidelity, making it a promising etching method for large-scale semiconductor manufacturing. In this research, small-scale MACE was demonstrated on silicon coupons with an initial process window of 0 nm - 100 nm oxide thickness. Then, a down-selected process window of 10 nm - 50 nm oxide thickness was successfully reproduced on a full-wafer scale (100 mm diameter silicon wafers) at different etchant solution concentrations. The oxide layer serves as a sacrificial layer between the silicon and resist to allow a consistent etching starting point, thus improving the etch depth uniformity and aspect ratios of silicon nanowires. The silicon nanowires were characterized using local scanning electron microscopy (SEM) images by mapping the areas of the wafer as North, South, East, and West to measure critical dimensions such as height and diameter, as well as to observe phenomena such as nanowire collapse

Download or read book Nanowires written by Anqi Zhang and published by Springer. This book was released on 2016-07-26 with total page 327 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive summary of nanowire research in the past decade, from the nanowire synthesis, characterization, assembly, to the device applications. In particular, the developments of complex/modulated nanowire structures, the assembly of hierarchical nanowire arrays, and the applications in the fields of nanoelectronics, nanophotonics, quantum devices, nano-enabled energy, and nano-bio interfaces, are focused. Moreover, novel nanowire building blocks for the future/emerging nanoscience and nanotechnology are also discussed.Semiconducting nanowires represent one of the most interesting research directions in nanoscience and nanotechnology, with capabilities of realizing structural and functional complexity through rational design and synthesis. The exquisite control of chemical composition, morphology, structure, doping and assembly, as well as incorporation with other materials, offer a variety of nanoscale building blocks with unique properties.

Download or read book Fabrication of Silicon Nanowires with Controlled Nano scale Shapes Using Wet Anisotropic Etching written by Bailey Anderson Yin and published by . This book was released on 2015 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: Silicon nanowires can enable important applications in energy and healthcare such as biochemical sensors, thermoelectric devices, and ultra-capacitors. In the energy sector, for example, as the need for more efficient energy storage continues to grow for enabling applications such as electric vehicles, high energy storage density capacitors are being explored as a potential replacement to traditional batteries that lack fast charge/discharge rates as well as have shorter life cycles. Silicon nanowire based ultra-capacitors offer increased energy storage density by increasing the surface area per unit projected area of the electrode, thereby allowing more surface “charge” to reside. The motivation behind this dissertation is the study of low-cost techniques for fabrication of high aspect ratio silicon nanowires with controlled geometry with an exemplar application in ultra-capacitors. Controlled transfer of high aspect ratio, nano-scale features into functional device layers requires anisotropic etch techniques. Dry reactive ion etch techniques are commonly used since most solution-based wet etch processes lack anisotropic pattern transfer capability. However, in silicon, anisotropic wet etch processes are available for the fabrication of nano-scale features, but have some constraints in the range of geometry of patterns that they can address. While this lack of geometric and material versatility precludes the use of these processes in applications like integrated circuits, they can be potentially realized for fabricating nanoscale pillars. This dissertation explores the geometric limitations of such inexpensive wet anisotropic etching processes and develops additional methods and geometries for fabrication of controlled nano-scale, high aspect ratio features. Jet and Flash Imprint Lithography (J-FILTM) has been used as the preferred pre-etch patterning process as it enables patterning of sub-50 nm high density features with versatile geometries over large areas. Exemplary anisotropic wet etch processes studied include Crystalline Orientation Dependent Etch (CODE) using potassium hydroxide (KOH) etching of silicon and Metal Assisted Chemical Etching (MACE) using gold as a catalyst to etch silicon. Experiments with CODE indicate that the geometric limitations of the etch process prevent the fabrication of high aspect ratio nanowires without adding a prohibitive number of steps to protect the pillar geometry. On the other hand, MACE offers a relatively simple process for fabricating high aspect ratio pillars with unique cross sections, and has thus been pursued to fabricate fully functional electrostatic capacitors featuring both circular and diamond-shaped nano-pillar electrodes. The capacitance of the diamond-shaped nano-pillar capacitor has been shown to be ~77.9% larger than that of the circular cross section due to the increase in surface area per unit projected area. This increase in capacitance approximately matches the increase calculated using analytical models. Thus, this dissertation provides a framework for the ability to create unique sharp cornered nanowires that can be explored further for a wider variety of cross sections.

Download or read book Advances in Nanomaterials written by Mushahid Husain and published by Springer. This book was released on 2016-03-15 with total page 439 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a review of the latest research findings and key applications in the field of nanomaterials. The book contains twelve chapters on different aspects of nanomaterials. It begins with key fundamental concepts to aid readers new to the discipline of nanomaterials, and then moves to the different types of nanomaterials studied. The book includes chapters based on the applications of nanomaterials for nano-biotechnology and solar energy. Overall, the book comprises chapters on a variety of topics on nanomaterials from expert authors across the globe. This book will appeal to researchers and professional alike, and may also be used as a reference for courses in nanomaterials.

Download or read book Nanowires for Energy Applications written by and published by Academic Press. This book was released on 2018-06-05 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanowires for Energy Applications, Volume 98, covers the latest breakthrough research and exciting developments in nanowires for energy applications. This volume focuses on various aspects of Nanowires for Energy Applications, presenting interesting sections on Electrospun semiconductor metal oxide nanowires for energy and sensing applications, Integration into flexible and functional materials, Nanowire Based Bulk Heterojunction Solar Cells, Semiconductor Nanowires for Thermoelectric Generation, Energy Scavenging: Mechanical, Thermoelectric, and Nanowire synthesis/growth methods, and more. - Features the latest breakthroughs and research and development in nanowires for energy applications - Covers a broad range of topics, including a wide variety of materials and many important aspects of solar fuels - Includes in-depth discussions on materials design, growth and synthesis, engineering, characterization and photoelectrochemical studies

Download or read book Photovoltaic Manufacturing written by Monika Freunek Muller and published by John Wiley & Sons. This book was released on 2021-08-16 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: PHOTOVOLTAIC MANUFACTURING This book covers the state-of-the-art and the fundamentals of silicon wafer solar cells manufacturing, written by world-class researchers and experts in the field. High quality and economic photovoltaic manufacturing is central to realizing reliable photovoltaic power supplies at reasonable cost. While photovoltaic silicon wafer manufacturing is at a mature, industrial and mass production stage, knowing and applying the fundamentals in solar manufacturing is essential to anyone working in this field. This is the first book on photovoltaic wet processing for silicon wafers, both mono- and multi-crystalline. The comprehensive book provides information for process, equipment, and device engineers and researchers in the solar manufacturing field. The authors of the chapters are world-class researchers and experts in their field of endeavor. The fundamentals of wet processing chemistry are introduced, covering etching, texturing, cleaning and metrology. New developments, innovative approaches, as well as current challenges are presented. Benefits of reading the book include: The book includes a detailed discussion of the important new development of black silicon, which is considered to have started a new wave in photovoltaics and become the new standard while substantially lowering the cost. Photovoltaics are central to any country’s “New Green Deal” and this book shows how to manufacture competitively. The book’s central goal is to show photovoltaic manufacturing can be done with enhanced quality and lowering costs. Audience Engineers, chemists, physicists, process technologists, in both academia and industry, that work with photovoltaics and their manufacture.

Download or read book Nanowires written by Ram K. Gupta and published by CRC Press. This book was released on 2023-03-14 with total page 429 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive resource covers the fundamentals of synthesis, characterizations, recent progress, and applications of nanowires for many emerging applications. Early chapters address their unique properties and morphology that enable their electronic, optical, and mechanical properties to be tuned. Later chapters address future perspectives and future challenges in areas where nanowires could provide possible solutions. All chapters are written by global experts, making this a suitable textbook for students and an up-to-date handbook for researchers and industry professionals working in physics, chemistry, materials, energy, biomedical, and nanotechnology. Covers materials, chemistry, and technologies for nanowires. Covers the state-of-the-art progress and challenges in nanowires. Provides fundamentals of the electrochemical behavior of various electrochemical devices and sensors. Offers insights on tuning the properties of nanowires for many emerging applications. Provides a new direction and understanding to scientists, researchers, and students.

Download or read book Advances in Emerging Solar Cells written by Munkhbayar Batmunkh and published by MDPI. This book was released on 2020-11-13 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photovoltaic (PV) cells, which directly convert sunlight into electricity, are renewable sources of energy that are sustainable and totally inexhaustible. Emerging classes of solar PV cells have drawn considerable attention because they provide significant advantages over traditional silicon solar cells, such as low cost and attractive designs (lightweight, flexible, and portable) while exhibiting promising performance. Despite these features, certain challenges restrict the possible commercialization of these technologies. The world's leading scientists are making numerous efforts focused on bringing these promising technologies closer to commercialization. Some of these scientists provided valuable research contributions to this Special Issue on “Advances in Emerging Solar Cells” published by Nanomaterials, MDPI. This Special Issue presents 12 excellent articles, 10 research and 2 review papers, covering perovskite solar cells, heterojunction solar cells, organic solar cells, dye-sensitized solar cells, and PV materials. We think that this Special Issue will attract significant attention from a broad research community including renewable energy, photovoltaic, emerging solar cells, material science and nanotechnology.