Papers by Keyword: Nanoelectronics

Abstract: This study presents electrical transport properties of a catalyst-free grown single aluminum nitride nanowire field effect transistor (AlNNW-FET) exhibiting a very high transconductance of 26.9 pS, high on/off current ratio of 795.9, high conductivity of 9.8 x 10^-4 Ω^-1.cm^-1, and a very low leakage current of 10 pA. The conductivity of AlN nanowire is two orders of magnitude higher than the reported studies. The AlNNW-FET reveals a dominant p-type conductivity. The p-type conductivity can be attributed to aluminum vacancies and complexes composed of Al vacancies and oxygen impurities. In consequence, the fabricated AlNNW-FET with high-performance, cost-effectiveness, and high-power efficiency is very well suited for use in low power and high temperature nanoelectronic and piezoelectric sensor applications, as well as integrated electro-optical devices including optomechanical devices and pyroelectric photodetectors.

Abstract: Modern electronics is based on semiconductor nanostructures in practically all main parts: from microprocessor circuits and memory elements to high frequency and light-emitting devices, sensors and photovoltaic cells. Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) with ultimately low gate length in the order of tens of nanometers and less is nowadays one of the basic elements of microprocessors and modern electron memory chips. Principally new physical peculiarities of semiconductor nanostructures are related to quantum effects like tunneling of charge carriers, controlled changing of energy band structure, quantization of energy spectrum of a charge carrier and a pronounced spin-related phenomena. Superposition of quantum states and formation of entangled states of photons offers new opportunities for the realization of quantum bits, development of nanoscale systems for quantum cryptography and quantum computing. Advanced growth techniques such as molecular beam epitaxy and chemical vapour epitaxy, atomic layer deposition as well as optical, electron and probe nanolithography for nanostructure fabrication have been widely used. Nanostructure characterization is performed using nanometer resolution tools including high-resolution, reflection and scanning electron microscopy as well as scanning tunneling and atomic force microscopy. Quantum properties of semiconductor nanostructures have been evaluated from precise electrical and optical measurements. Modern concepts of various semiconductor devices in electronics and photonics including single-photon emitters, memory elements, photodetectors and highly sensitive biosensors are developed very intensively. The perspectives of nanostructured materials for the creation of a new generation of universal memory and neuromorphic computing elements are under lively discussion. This paper is devoted to a brief description of current achievements in the investigation and modeling of single-electron and single-photon phenomena in semiconductor nanostructures, as well as in the fabrication of a new generation of elements for micro-, nano, optoelectronics and quantum devices.

Abstract: Novel nanocomposite made of one-dimensional (1-D) multi-walled carbon nanotube (MWCNT) and two-dimensional (2-D) graphene was prepared. MWCNT was spin coated onto copper foil and followed by chemical vapor deposition (CVD) growth of graphene. The MWCNT-Graphene nanocomposite was transferred onto target substrate by using a standard polymer-based transfer technique. HRTEM and Raman spectroscopy showed high crystallinity of fused MWCNT and graphene layer. Low defect-related D-peak was also observed even after the nanocomposite underwent high temperature processing. As compared to pristine graphene, electrical characterization of MWCNT-Graphene nanocomposite also revealed the reduction of sheet resistance by ~71% and almost 2-fold improvement in room-temperature carrier mobility. These improvements are surmised due to additional conducting channels formed by MWCNT in the graphene layer. Hence, higher electrical conductivity can be expected. With the introduction of MWCNT across the graphene layer, highly desirable electrical properties can be achieved and as such leveraging the viability of graphene-based nanoelectronics devices.

Abstract: Anodic aluminum oxide (AAO) is well known for its nanoscopic structures and its applications in microfluidics, sensors and nanoelectronics. The pore density, the pore diameter, and the interpore distance of an AAO substrate can be controlled by varying anodization process conditions. In this research, the self-organized two-step anodization is carried out with a low-grade (Al6061) aluminium substrate using a 40V voltage at the temperature of 2 to 5 °C. Three experiments are done with the anodization time of 24 hours, 48 hours and 72 hours. The structural features of AAO are characterized by a field emission electron microscope (FE-SEM). The data from FE-SEM show that the average pore diameter increases with the anodization time, and that the Al6061 aluminium substrate can be used to fabricate a nanoporous AAO film with an average pore diameter smaller than 17 nanometers.

Abstract: In the present work, we demonstrate the theoretical feasibility of basic logic gates consisting of dipole-coupled Dronpa molecules, potentially permitting the realization of nanoscale, low energy consuming and dissipating, terahertz-frequency computers and digital signal processors. The operational principle is related to an experimentally demonstrated, electric field-induced switching behavior of proteins.

Abstract: Mongolia is a consumer of e-products and their parts are imported from abroad. Currently, e-waste represents the biggest and fastest growing manufacturing waste. The objectives of this study are collecting and analyzing data from statistical reports of Mongolia and comparing them to other countries, and recommending an infrastructure of e-waste management in the existing legal environment. Thereby, all data was published by governmental entities and central statistical bureaus. An e-product, such as computers and TV’s are leading by their imported quantity in Mongolia. The e-waste is becoming one of the most challenging environmental issues because of its tendency to be incompatible for reuse and recycling. However, up to now, a main portion of e-waste is utilized through re-using (45.1%) and disposing (31.9%), and fewer amounts are recycled (23.0%) as was estimated in a study supported with the Japanese International Cooperation Agency (JICA), Japan, 2010. In conclusion, Mongolia needs to establish e-waste management by implementing core activities such as adapting experiences from high developed countries, harmonizing the corporation between in governmental entities and supporting business activities of recyclers and retailers. The green development policy was approved by the Mongolian Parliament in June, 2014. According to this new policy, it is needed to be applied recycling incentives to raise the environmental awareness of all stakeholders.

Abstract: The technical and economic growth of the twentieth century was marked by evolution of electronic devices and gadgets. The day-to-day lifestyle has been significantly affected by the advancement in communication systems, information systems and consumer electronics. The lifeline of progress has been the invention of the transistor and its dynamic up-gradation. Discovery of fabricating Integrated Circuits (IC’s) revolutionized the concept of electronic circuits. With advent of time the size of components decreased, which led to increase in component density. This trend of decreasing device size and denser integrated circuits is being limited by the current lithography techniques. Non-uniformity of doping, quantum mechanical tunneling of electrons from source to drain and leakage of electrons through gate oxide limit scaling down of devices. Heat dissipation and capacitive coupling between circuit components becomes significant with decreasing size of the components. Along with the intrinsic technical limitations, downscaling of devices to nanometer sizes leads to a change in the physical mechanisms controlling the charge propagation. To deal with this constraint, the search is on to look around for alternative materials for electronic device application and new methods for electronic device fabrication. Such material is comprised of organic molecules, proteins, carbon materials, DNA and the list is endless which can be grown in the laboratory. Many molecules show interesting electronic properties, which make them probable candidates for electronic device applications. The challenge is to interpret their electronic properties at nanoscale so as to exploit them for use in new generation electronic devices. Need to trim downsize and have a higher component density have ushered us into an era of nanoelectronics.

Abstract: The paper deals with the necessity to develop and apply quantitative methods to the process of sorting and systematization of physics’ content, when future engineers are training physics. Consistency of the information theory’s methods and processes of the human’s information perception is emphasized. The sense structure of a physical term and graph of such structure, which are based on the information model of intra-subject connections, are given. It is shown that, using the sense structure graph of a physical term, the information characteristics of such term may be calculated. Nanoelectronics developes very fast, and students need to study many different disciplines. On the base of these characteristics we can fixed the information limitations to escape students overloading.

Abstract: The existence of the fourth fundamental circuit element, the memristor, was first postulated over 30 years ago by Leon Chua. The implementation of the first modern memristor prototype by Hewlett Packard Laboratories in 2008 initiated a great scientific interest for these unique nanoelectronic devices and currently, there is a growing variety of systems that exhibit memristive behavior. However, most of the research has focused on the properties of the single devices, therefore very little is known about their response when these devices are organized into networks. In this work, the composite characteristics of memristive elements connected in network configurations are studied and the relationships among the single devices are investigated. We finally show how the threshold-dependent nonlinear memristive behavior could be elaborated to make possible the development of novel and sophisticated digital/analog memristive nanosystems.

Abstract: Graphene is a form of carbon just one atom thick, it has an array of physical properties that promise to revolutionize electronics and other technical fields. Since the first reports of its discovery in 2004, work on graphene has largely stressed understanding the fundamentals of the two-dimensional material over pursuing applications for it. Graphene may become a key enabling material, paving the way for a new generation of high-speed nanoscale electronics with consequences and breakthroughs similar to that of silicon’s in the last few decades. In this paper we present the evolution of this fascinating material, beginning with early observations and moving into the practical applications.