Download or read book Fabrication and Characterization of Single Electron Device and Study of Energy Filtering in Single Electron Transport written by Liang-Chieh Ma and published by . This book was released on 2014 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: Single electron devices, in which transport of single electrons is precisely controlled, hold a great promise as important components of future electronic devices and sensors. However, technical challenges have prevented their implementations to practical electronic and sensing systems. First of all, the fabrication of single electron devices requires their components to be defined and arranged in nanoscale precision, a great challenge for a large-scale fabrication. Secondly, for room temperature operation, the single-electron charging energy should be much larger than the room-temperature thermal energy, ~25 meV, requiring use of extremely small Coulomb island, which is difficult to control. This has limited the operation of most single-electron devices to low temperatures, requiring liquid N2 or liquid He cooling, a great obstacle for practical applications. In this thesis, I present systematic study to address these critical problems. First, I demonstrate a method which allows large scale fabrication of single electron devices using CMOS compatible processing technology. Second, I demonstrate a method that suppresses the thermal excitation of electrons and cools down electron temperature, enabling room-temperature operation of single electron devices. By analyzing the single electron device from statistical thermodynamics point of view, a model was constructed to describe single-electron tunneling events. In this model, the free energy change associated with a single tunneling event was formulated, from which the tunneling rates were calculated using the Fermi Golden rule. The I-V characteristics calculated from this model were in exact match with the widely used single electron device simulator SIMON. A new vertically aligned electrode structure of single electron device was designed and fabricated. CMOS-compatible fabrication process allowed a large scale fabrication of single electron devices. The source and drain were stacked vertically and separated by a thin dielectric layer (~10 nm). The deposition of dielectric layers was well controlled using PECVD (plasma-enhanced chemical vapor deposition) or ALD (atomic layer deposition). Gold nanoparticles serving as Coulomb islands were attached on the exposed sidewall of the dielectric layer. Most importantly, a quantum well structure was formed between the source and tunneling barrier. The discrete energy state of the quantum well was utilized as an energy filter, serving as a key component for room-temperature operation of single electron devices. Clear Coulomb blockade, Coulomb staircase and Coulomb oscillation were demonstrated at room temperature by the fabricated single electron devices. I-V measurements done at different temperatures showed suppression in Fermi-Dirac thermal smearing. This was attributed to the electron energy filtering through the discrete energy level of the quantum well. When electron tunnels between the quantum well and Coulomb island, the energy distribution of electrons is squeezed. Through this energy filtering effect, cold electrons whose temperature is as low as ~45K can be created and transported at room temperature without physically cooling the device. Since the tunnel junctions play an important role for the single electron transport, a new structure of single electron device was proposed in order to gain more control in manipulating the tunnel junctions. A structure of silicon nanopillar single electron device was proposed and its fabrication procedure was designed. Cr nanopillars were fabricated to demonstrate the feasibility of the proposed nanopillar single electron device. In fabricating nanoscale devices, precise placement of nanoscale objects (e.g. nanoparticles) onto targeted substrate positions is critical. A new method for precise placement of nanoparticles, electrostatic funneling, was developed. In this method, the electrostatic guiding structure formed using self-assembled monolayers of organic molecules guides charged nanoparticles onto desired target positions with nanoscale precision. This electrostatic funneling method could be used to increase the yield of single electron device fabrication.

Download or read book Fabrication and Characterization of Hybrid Single Electron Devices written by Emanuele Enrico and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design and Fabrication of Electron Energy Filters for Room Temperature Inelastic Electron Tunneling Spectroscopy written by Prashant Patil (S.M.) and published by . This book was released on 2013 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: Odor detection has wide range of applications in a variety of industries, including the agricultural, clinical diagnosis, pharmaceutical, cosmetics, food analysis, environmental and defense fields. Spectroscopic techniques such as FTIR and Raman are commonly used for electronic nose application. However, their application is limited by factors such as poor sensitivity, selectivity and non-portability. Inelastic electron tunneling spectroscopy (IETS) is an all electronic spectroscopy that has been extensively used to measure the vibrational modes of molecules and can be used for electronic nose application. It has several advantages such as ultra-high sensitivity and compact size. However, IETS requires cryogenic temperature to resolve molecular spectra, which limits its use in electronic nose application. A new theory of biological olfaction postulates that the odorant detectors inside a nose recognize an odorant's vibrations via inelastic electron tunneling (Turin, 1996). However, a biological system works at room temperature but conventional IET spectroscopy requires cryogenic temperatures. Thus posing the following question: Is it possible to resolve molecular vibrational spectra using inelastic electron tunneling spectroscopy at room temperature? IET spectroscopy involves the tunneling of electrons through an insulating barrier that is situated between two conducting metal electrodes. At room temperature, tunneling electrons possess thermal energy and occupy broad distribution of energy levels available in metals. This thermal distribution of electrons drastically reduces the resolution of IET spectroscopy. By reducing the thermal distribution of tunneling electrons at room temperature, we can increase the resolution of IET spectroscopy. The objective of this work is to develop electron energy filters to narrow down the thermal energy distribution of electrons at room temperature. I further evaluate the application of these electron energy filters to increase the resolution of IET spectroscopy at room temperature. Some recent advancements in nanomaterials, such as quantum dots with discrete electron energy levels are an excellent choice as electron energy filters. In metals, the continuous distribution of available energy states causes broad thermal distribution of electrons at room temperature. In contrast, quantum dots have discrete energy levels due to their small size. So even though electrons might possess thermal energy at room temperature, they can only occupy the discrete energy levels available in quantum dots. Hence, the thermal energy distribution of electrons can be narrowed down to the energy levels available in quantum dots. The electron energy filter designed in this work, consists of a 2-dimensional array of CdSe quantum dots of sizes around 2.5nm sandwiched between metal electrodes. Through electrical characterization of these devices, we can conclude that they can narrow down thermal distribution of electrons from 25meV down to around 10meV. However, to resolve the molecular vibrational energy level at room temperature, thermal energy distribution of electrons should be less than 6.6meV. Since array of quantum dots results in formation of energy minibands, this work suggests that single quantum dot should be used instead of array of dots to improve the performance of electron energy filters. Moreover, the study of electron transport through single quantum dots done in this work suggests that the size of the dot should be less than 2.5nm to be used in room temperature IET spectroscopy. Interestingly, this length scale is consistent with the size of donor and acceptor sites in odorant receptors potentially explaining how these receptors could be able to resolve molecular spectra at room temperatures.

Download or read book Recueil de travaux publ l occasion de l Assembl e de la Soci t suisse des juristes Gen ve du 3 au 5 octobre 1969 written by and published by . This book was released on 1969 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy Level Alignment and Electron Transport Through Metal Organic Contacts written by Enrique Abad and published by Springer Science & Business Media. This book was released on 2012-09-15 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, ever more electronic devices have started to exploit the advantages of organic semiconductors. The work reported in this thesis focuses on analyzing theoretically the energy level alignment of different metal/organic interfaces, necessary to tailor devices with good performance. Traditional methods based on density functional theory (DFT), are not appropriate for analyzing them because they underestimate the organic energy gap and fail to correctly describe the van der Waals forces. Since the size of these systems prohibits the use of more accurate methods, corrections to those DFT drawbacks are desirable. In this work a combination of a standard DFT calculation with the inclusion of the charging energy (U) of the molecule, calculated from first principles, is presented. Regarding the dispersion forces, incorrect long range interaction is substituted by a van der Waals potential. With these corrections, the C60, benzene, pentacene, TTF and TCNQ/Au(111) interfaces are analyzed, both for single molecules and for a monolayer. The results validate the induced density of interface states model.

Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1967 with total page 1102 pages. Available in PDF, EPUB and Kindle. Book excerpt: NSA is a comprehensive collection of international nuclear science and technology literature for the period 1948 through 1976, pre-dating the prestigious INIS database, which began in 1970. NSA existed as a printed product (Volumes 1-33) initially, created by DOE's predecessor, the U.S. Atomic Energy Commission (AEC). NSA includes citations to scientific and technical reports from the AEC, the U.S. Energy Research and Development Administration and its contractors, plus other agencies and international organizations, universities, and industrial and research organizations. References to books, conference proceedings, papers, patents, dissertations, engineering drawings, and journal articles from worldwide sources are also included. Abstracts and full text are provided if available.

Download or read book Handbook of Single Molecule Electronics written by Kasper Moth-Poulsen and published by CRC Press. This book was released on 2016-01-05 with total page 439 pages. Available in PDF, EPUB and Kindle. Book excerpt: Single-molecule electronics has evolved as a vibrant research field during the last two decades. The vision is to be able to create electronic components at the highest level of miniaturization-the single molecule. This book compiles and details cutting-edge research with contributions from chemists, physicists, theoreticians, and engineers. It cov

Download or read book Simulation of Single electron Devices written by Andreas Scholze and published by . This book was released on 2000 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Electronic Device Fabrication and Characterization Based on Two dimensional Materials written by Zhengfeng Yang and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2692 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 643 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 Field effects on Single Molecular Circuitry written by Albert Cortijos i Aragonès and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Inspired by the proposal that single molecules will be functional elements of future nanoelectronic and Spintronics devices, there exists considerable interest in understanding charge transport in individual molecular backbones. To investigate charge transport in single-molecule devices, in the presented thesis is exploit scanning tunneling microscopy-based approaches in the break-junction mode (STM-BJ) designed by Xu and Tao in 2003 under the effects of magnetic and electric force fields, which divide the thesis in two parts. The first block of the first part of the thesis is presented a study performed at room-temperature based on spin-dependent transport in single-molecule devices employing on thermal spin-crossover metal complexes. Here is shown that the interfacial magnetism or Spinterface, resulting from the interaction between a magnetic molecule and a metal surface, becomes the key pillar to engineer nanoscale molecular devices with novel spin-based functionalities, such as conductance switching based on a Spinfilter, because has the capability to spin-polarize the injected current through it. Also in this block are defined the required conditions which have to be gathered by any molecule to behaves as spin-filtering: be paramagnetic and susceptible to an aligned by external magnetic field, interact with the junction metal electrodes enough strongly through the extended electronic states and also present close energy values to the "fermi energy" for one of the electronic spins allowing its transport. The observed results can be summarized as a high magnetoresistive efficiency of two orders of magnitude (10000%) between the two magnetic field orientations. In the second block of the first part is presented a novel way to form highly conductive and tunable molecular wires exploiting supramolecular chemistry schemes. Single metalloporphyrin rings are wired from its metallic center by using strong Lewis bases, resulting in an increase of the conductivity of three orders of magnitude versus previous single-porphyrin wires. This novel platform of wiring individual porphyrins mimics the way nature exploits these systems by orienting the perpendicular porphyrin axis as the easy axis for electron/energy transfer. Employing this new perpendicular molecule's orientation, spin-depending current measurements were performed following the procedure of the first block using Cu and Co metalloporphyrins. results Spinfilter-switch effect. The observed results can be summarized as a medium magnetoresistive efficiency ca. factor 2-4 between the two magnetic field orientations. The third block of the first part is focused on Spin selectivity induced by electron transport through chiral molecules (CISS) replacing the paramagnetic character of the device's central molecules previously studied. A new method to quantify the spin polarization power of chiral molecules is presented using a junction of either a Dextro- or Levo- 22 amino-acid peptide coupled to an Au surface and to a magnetized Ni contact. As a consequence of the molecular property of helicity filtering and the asymmetry in the density of states at the ferromagnetic electrode, the results show how the conductance can be separated in electron helicity channels where the largest contribution is correlated with the molecular filtering effect in the spin-polarized transport through the chiral peptide. In the second part and based on using external electric fields, is demonstrated the use of the STM-BJ approach to study basic mechanisms in chemical catalysis at the nanoscale. Is designed a surface model system to probe electric field catalysis of a Diels-Alder reaction by delivering an oriented electrical field-stimulus across two reactants: a diene, attached to the STM tip electrode and a dienophile attached to the substrate electrode. This method enables studying chemical reactions at the single-molecule level. Was observed how only an external electric field aligned in the specific way respect to the reaction center and pointing from the diene (bearing a negative charge) to the dienophile (bearing a positive charge) can accelerate the Diels-Alder reaction process. Besides using the external electric field strength as tool was possible to tune the reaction processes." -- TDX.

Download or read book Electrical Electronics Abstracts written by and published by . This book was released on 1997 with total page 2304 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development Fabrication and Characterization of Transparent Electronic Devices written by Randy L. Hoffman and published by . This book was released on 2002 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this thesis is to provide an initial demonstration of the feasibility of constructing highly transparent active electronic devices. Such a demonstration is successfully achieved in the fabrication of ZnO-based thin film transistors (TFTs) exhibiting transparency greater than ~90% in the visible portion of the electromagnetic spectrum and prototypical n-channel, enhancement mode TFT characteristics. Electrical characterization studies of these ZnO-based transparent TFTs and of CuYO2 / ZnO / ITO p-i-n heterojunction diodes serve to elucidate the mechanisms responsible for the behavior of these devices in particular, and of transparent electronic devices in general. Energy band analysis of the degenerate semiconductor / insulator heterojunction yields insight into the phenomenon of charge injection into an insulator, with important implications for the analysis of devices containing heterojunctions of this nature. Finally, a novel technique for simultaneously characterizing carrier injection into an insulator and interface channel formation, the capacitance-(voltage, frequency) [C-(V, f)] technique, is proposed and employed in the characterization of ZnO-based TFT structures.

Download or read book ERDA Energy Research Abstracts written by and published by . This book was released on 1989 with total page 848 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2007 with total page 960 pages. Available in PDF, EPUB and Kindle. Book excerpt: