Journal articles on the topic 'Metal oxide semiconductors – Design and construction'
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Maity, Heranmoy. "A New Approach to Design and Implementation of 2-Input XOR Gate Using 4-Transistor." Micro and Nanosystems 12, no. 3 (December 1, 2020): 240–42. http://dx.doi.org/10.2174/1876402912666200309120205.
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Aim: This paper proposed the design and implementation of a 2-input XOR gate using 4- transistor. Method : The XOR gate can be designed using NOT gate and 2:1 multiplexer. The NOT gate is designed using two metal–oxide–semiconductor field-effect transistors MOSFETs and an approximate 2:1 multiplexer. The 2:1 multiplexer is designed using two MOSFETs. So, an XOR gate can be designed using four transistors. Results: The proposed work theoretically and experimentally describes the 2-input XOR gate using 4- transistor. The proposed work was verified using Xilinx (ISE Design Suite).
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Li, Le, Xiaofei Ma, Yin Xiao, and Yong Wang. "Construction and Application of Graphene Oxide-Bovine Serum Albumin Modified Extended Gate Field Effect Transistor Chiral Sensor." Sensors 21, no. 11 (June 7, 2021): 3921. http://dx.doi.org/10.3390/s21113921.
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Chirality is an essential natural attribute of organisms. Chiral molecules exhibit differences in biochemical processes, pharmacodynamics, and toxicological properties, and their enantioselective recognition plays an important role in explaining life science processes and guiding drug design. Herein, we developed an ultra-sensitive enantiomer recognition platform based on an extended-gate metal-oxide semiconductor field-effect-transistor (Nafion–GO@BSA–EG-MOSFET) that achieved effective chiral resolution of ultra-sensitive Lysine (Lys) and α-Methylbenzylamine (α-Met) enantiodiscrimination at the femtomole level. Bovine serum albumin (BSA) was immobilized on the surface of graphene oxide (GO) through amide bond coupling to prepare the GO@BSA complex. GO@BSA was drop-cast on deposited Au surfaces with a Nafion solution to afford the extended-gate sensing unit. Effective recognition of chiral enantiomers of mandelic acid (MA), tartaric acid (TA), tryptophan (Trp), Lys and α-Met was realized. Moreover, the introduction of GO reduced non-specific adsorption, and the chiral resolution concentration of α-Met reached the level of picomole in a 5-fold diluted fetal bovine serum (FBS). Finally, the chiral recognition mechanism of the as-fabricated sensor was proposed.
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Sotner, Roman, Jan Jerabek, Ladislav Polak, Roman Prokop, and Vilem Kledrowetz. "Integrated Building Cells for a Simple Modular Design of Electronic Circuits with Reduced External Complexity: Performance, Active Element Assembly, and an Application Example." Electronics 8, no. 5 (May 22, 2019): 568. http://dx.doi.org/10.3390/electronics8050568.
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This paper introduces new integrated analog cells fabricated in a C035 I3T25 0.35-μm ON Semiconductor process suitable for a modular design of advanced active elements with multiple terminals and controllable features. We developed and realized five analog cells on a single integrated circuit (IC), namely a voltage differencing differential buffer, a voltage multiplier with current output in full complementary metal–oxide–semiconductor (CMOS) form, a voltage multiplier with current output with a bipolar core, a current-controlled current conveyor of the second generation with four current outputs, and a single-input and single-output adjustable current amplifier. These cells (sub-blocks of the manufactured IC device), designed to operate in a bandwidth of up to tens of MHz, can be used as a construction set for building a variety of advanced active elements, offering up to four independently adjustable internal parameters. The performances of all individual cells were verified by extensive laboratory measurements, and the obtained results were compared to simulations in the Cadence IC6 tool. The definition and assembly of a newly specified advanced active element, namely a current-controlled voltage differencing current conveyor transconductance amplifier (CC-VDCCTA), is shown as an example of modular interconnection of the selected cells. This device was implemented in a newly synthesized topology of an electronically linearly tunable quadrature oscillator. Features of this active element were verified by simulations and experimental measurements.
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Demkov, Alexander A., Xiaodong Zhang, and Heather Loechelt. "Theoretical Investigation of Ultrathin Gate Dielectrics." VLSI Design 13, no. 1-4 (January 1, 2001): 135–43. http://dx.doi.org/10.1155/2001/98032.
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We describe a theoretical methodology for screening potential gate dielectric materials. A recently proposed method for constructing realistic structural models of the Si-dielectric interface is used to generate the Si-SiO2-Si and Si-SiON-SiO2-Si model metal-oxide-semiconductor (MOS) structures. We discuss methods to estimate the valence band discontinuity at the corresponding interface. We use Landauer's ballistic transport approach to investigate the low bias leakage through these ultrathin dielectric layers.
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Breslin, Catherine, and Adrian O'Lenskie. "Neuromorphic hardware databases for exploring structure–function relationships in the brain." Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 356, no. 1412 (August 29, 2001): 1249–58. http://dx.doi.org/10.1098/rstb.2001.0904.
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Neuromorphic hardware is the term used to describe full custom–designed integrated circuits, or silicon ‘chips’, that are the product of neuromorphic engineering—a methodology for the synthesis of biologically inspired elements and systems, such as individual neurons, retinae, cochleas, oculomotor systems and central pattern generators. We focus on the implementation of neurons and networks of neurons, designed to illuminate structure–function relationships. Neuromorphic hardware can be constructed with either digital or analogue circuitry or with mixed–signal circuitry—a hybrid of the two. Currently, most examples of this type of hardware are constructed using analogue circuits, in complementary metal–oxide–semiconductor technology. The correspondence between these circuits and neurons, or networks of neurons, can exist at a number of levels. At the lowest level, this correspondence is between membrane ion channels and field–effect transistors. At higher levels, the correspondence is between whole conductances and firing behaviour, and filters and amplifiers, devices found in conventional integrated circuit design. Similarly, neuromorphic engineers can choose to design Hodgkin–Huxley model neurons, or reduced models, such as integrate–and–fire neurons. In addition to the choice of level, there is also choice within the design technique itself; for example, resistive and capacitive properties of the neuronal membrane can be constructed with extrinsic devices, or using the intrinsic properties of the materials from which the transistors themselves are composed. So, silicon neurons can be built, with dendritic, somatic and axonal structures, and endowed with ionic, synaptic and morphological properties. Examples of the structure–function relationships already explored using neuromorphic hardware include correlation detection and direction selectivity. Establishing a database for this hardware is valuable for two reasons: first, independently of neuroscientific motivations, the field of neuromorphic engineering would benefit greatly from a resource in which circuit designs could be stored in a form appropriate for reuse and re–fabrication. Analogue designers would benefit particularly from such a database, as there are no equivalents to the algorithmic design methods available to designers of digital circuits. Second, and more importantly for the purpose of this theme issue, is the possibility of a database of silicon neuron designs replicating specific neuronal types and morphologies. In the future, it may be possible to use an automated process to translate morphometric data directly into circuit design compatible formats. The question that needs to be addressed is: what could a neuromorphic hardware database contribute to the wider neuroscientific community that a conventional database could not? One answer is that neuromorphic hardware is expected to provide analogue sensory–motor systems for interfacing the computational power of symbolic, digital systems with the external, analogue environment. It is also expected to contribute to ongoing work in neural–silicon interfaces and prosthetics. Finally, there is a possibility that the use of evolving circuits, using reconfigurable hardware and genetic algorithms, will create an explosion in the number of designs available to the neuroscience community. All this creates the need for a database to be established, and it would be advantageous to set about this while the field is relatively young. This paper outlines a framework for the construction of a neuromorphic hardware database, for use in the biological exploration of structure–function relationships.
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Sun, Peng. "Gas Sensors Based on Oxide Semiconductors with Porous Nanostructures." Proceedings 14, no. 1 (June 19, 2019): 13. http://dx.doi.org/10.3390/proceedings2019014013.
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Gas sensor as a device composed of sensing material coupled with signal transducer, has been acknowledged as an analytical tool for detection and quantification of inflammable, explosive or toxic gases. The gas sensors based on nanostructured oxide semiconductor endowed with excellent sensing properties have exhibited great potential application in the fields of environmental monitoring, resource exploration, medical welfare, etc. It is well known that the sensing mechanism of sensor employing oxide semiconductors is mainly that the interactions between the surface adsorbed oxygen species and target gases lead to a change in the electrical conductivity. Therefore, the gas sensing properties of oxide semiconductors are closely related with their composition, crystalline size, and microstructure. In this regard, design and preparation of oxides with novel architectures will be increasingly important in the construction of high performance gas sensors. Due to high specific surface area, low density, and good surface permeability, porous nanostructures oxide semiconductor sensing materials have attracted growing interest in recent years. In our work, we successfully prepared various porous nanostructures oxides and their composites to the construction of high performances gas sensors with enhanced sensitivity, selectivity, as well as lowered detection limit. The subsequent gas sensing measurements explicitly revealed that these oxides and composites manifested superior sensing behaviors (like much higher sensitivity and faster response speed), which can be ascribed to the porous architectures and the synergistic effects.
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Argazzi, Roberto, Neyde Yukie Murakami Iha, Hervé Zabri, Fabrice Odobel, and Carlo Alberto Bignozzi. "Design of molecular dyes for application in photoelectrochemical and electrochromic devices based on nanocrystalline metal oxide semiconductors." Coordination Chemistry Reviews 248, no. 13-14 (July 2004): 1299–316. http://dx.doi.org/10.1016/j.ccr.2004.03.026.
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Pargoletti, Eleonora, and Giuseppe Cappelletti. "Breakthroughs in the Design of Novel Carbon-Based Metal Oxides Nanocomposites for VOCs Gas Sensing." Nanomaterials 10, no. 8 (July 29, 2020): 1485. http://dx.doi.org/10.3390/nano10081485.
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Nowadays, the detection of volatile organic compounds (VOCs) at trace levels (down to ppb) is feasible by exploiting ultra-sensitive and highly selective chemoresistors, especially in the field of medical diagnosis. By coupling metal oxide semiconductors (MOS e.g., SnO2, ZnO, WO3, CuO, TiO2 and Fe2O3) with innovative carbon-based materials (graphene, graphene oxide, reduced graphene oxide, single-wall and multi-wall carbon nanotubes), outstanding performances in terms of sensitivity, selectivity, limits of detection, response and recovery times towards specific gaseous targets (such as ethanol, acetone, formaldehyde and aromatic compounds) can be easily achieved. Notably, carbonaceous species, highly interconnected to MOS nanoparticles, enhance the sensor responses by (i) increasing the surface area and the pore content, (ii) favoring the electron migration, the transfer efficiency (spillover effect) and gas diffusion rate, (iii) promoting the active sites concomitantly limiting the nanopowders agglomeration; and (iv) forming nano-heterojunctions. Herein, the aim of the present review is to highlight the above-mentioned hybrid features in order to engineer novel flexible, miniaturized and low working temperature sensors, able to detect specific VOC biomarkers of a human’s disease.
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Anusha, N., and T. Sasilatha. "Performance Analysis of Wide AND OR Structures Using Keeper Architectures in Various Complementary Metal Oxide Semiconductors Technologies." Journal of Computational and Theoretical Nanoscience 13, no. 10 (October 1, 2016): 6999–7008. http://dx.doi.org/10.1166/jctn.2016.5660.
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Power dissipation and area are the important constraints in VLSI design. Various techniques are employed in reducing the power dissipation of the logic circuits. Dynamic CMOS circuits are one of the techniques in VLSI to lower the power dissipation. All gates can be designed using dynamic CMOS to lower the power dissipation. In this paper wide AND OR gates are implemented using Dynamic circuits, where keeper architecture is employed in order to prevent leakage current and to ensure that correct output is obtained. The performance analysis of Wide AND OR structures implemented in dynamic CMOS with mandatory keeper architectures in ultra submicron range are analyzed. A comparative analysis of Power dissipation and area of the keeper architectures employed in dynamic CMOS in different lower nanometer such as 120 nm, 90 nm, 70 nm and 50 nm is analyzed.
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Pathan, Abrarkhan M., Dhawal H. Agrawal, Pina M. Bhatt, Hitarthi H. Patel, and U. S. Joshi. "Design and Construction of Low Temperature Attachment for Commercial AFM." Solid State Phenomena 209 (November 2013): 137–42. http://dx.doi.org/10.4028/www.scientific.net/ssp.209.137.
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With the rapid advancements in the field of nanoscience and nanotechnology, scanning probe microscopy has become an integral part of a typical R&D lab. Atomic force microscope (AFM) has become a familiar name in this category. The AFM measures the forces acting between a fine tip and a sample. The tip is attached to the free end of a cantilever and is brought very close to a surface. Attractive or repulsive forces resulting from interactions between the tip and the surface will cause a positive or negative bending of the cantilever. The bending is detected by means of a laser beam, which is reflected from the backside of the cantilever. Atomic force microscopy is currently applied to various environments (air, liquid, vacuum) and types of materials such as metal semiconductors, soft biological samples, conductive and non-conductive materials. With this technique size measurements or even manipulations of nano-objects may be performed. An experimental setup has been designed and built such that a commercially available Atomic Force Microscope (AFM) (Nanosurf AG, Easyscan 2) can be operated at cryogenic temperature under vacuum and in a vibration-free environment. The design also takes care of portability and flexibility of AFM i.e. it is very small, light weight and AFM can be used in both ambient and cryogenic conditions. The whole set up was assembled in-house at a fairly low cost. It is used to study the surface structure of nanomaterials. Important perovskite manganite Pr0.7Ca0.3MnO3thin films were studied and results such as morphology, RMS area and line roughness as well as the particle size have been estimated at cryogenic temperature.
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Sandoval-Ríos, C., M. Nieto-Pérez, Jorge A. Huerta, J. Pineda-Piñón, and E. Rodríguez-Vázquez. "An experimental facility to study film growth on liquid phase, condensation and melting in downward-facing substrates." Superficies y Vacío 31, no. 2 (June 14, 2018): 26–32. http://dx.doi.org/10.47566/2018_syv31_1-020026.
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Film growth, condensation and melting of materials are very important physical processes, involved in the development of semiconductor related industry processes, alkali metals and their oxides, and recently in nuclear fusion projects. The growth of low melting point thin films via liquid phase epitaxy (LPE) has drawn attention especially for the manufacture of semiconductor compounds containing indium, gallium, tin, lithium and their alloys, all characterized by a low melting point. That allows the growth of films in the liquid phase and subsequent control on crystallization morphology by manipulating quenching conditions. LPE yields highly crystalline either thin (a few nm) or thick (100s of µm) films with high purity. If LPE is performed in downward-facing substrates, Rayleigh-Taylor instabilities appear, and this effect of gravity in the film growth has not been studied in depth. This paper presents the design, construction and preliminary testing of an experimental facility to study film growth from the liquid phase, and also condensation and melting processes. This facility consists of a thermal evaporator and a substrate holder where samples are placed facing down. The size of the sample holder and the ability to achieve controlled thermal gradients across it, would allow the study of temperature effect in grown films morphology, and also in condensation and melting phenomena such as dripping onset and critical angle for film/drop displacement. Besides, system allows to study condensation modes and surface roughness on the condensation dynamics of liquid films growing from the vapor phase.
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Garcia-Peiro, Jose I., Javier Bonet-Aleta, Carlos J. Bueno-Alejo, and Jose L. Hueso. "Recent Advances in the Design and Photocatalytic Enhanced Performance of Gold Plasmonic Nanostructures Decorated with Non-Titania Based Semiconductor Hetero-Nanoarchitectures." Catalysts 10, no. 12 (December 14, 2020): 1459. http://dx.doi.org/10.3390/catal10121459.
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Plasmonic photocatalysts combining metallic nanoparticles and semiconductors have been aimed as versatile alternatives to drive light-assisted catalytic chemical reactions beyond the ultraviolet (UV) regions, and overcome one of the major drawbacks of the most exploited photocatalysts (TiO2 or ZnO). The strong size and morphology dependence of metallic nanostructures to tune their visible to near-infrared (vis-NIR) light harvesting capabilities has been combined with the design of a wide variety of architectures for the semiconductor supports to promote the selective activity of specific crystallographic facets. The search for efficient heterojunctions has been subjected to numerous studies, especially those involving gold nanostructures and titania semiconductors. In the present review, we paid special attention to the most recent advances in the design of gold-semiconductor hetero-nanostructures including emerging metal oxides such as cerium oxide or copper oxide (CeO2 or Cu2O) or metal chalcogenides such as copper sulfide or cadmium sulfides (CuS or CdS). These alternative hybrid materials were thoroughly built in past years to target research fields of strong impact, such as solar energy conversion, water splitting, environmental chemistry, or nanomedicine. Herein, we evaluate the influence of tuning the morphologies of the plasmonic gold nanostructures or the semiconductor interacting structures, and how these variations in geometry, either individual or combined, have a significant influence on the final photocatalytic performance.
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Palma, Fabrizio. "Self-Mixing Model of Terahertz Rectification in a Metal Oxide Semiconductor Capacitance." Electronics 9, no. 3 (March 14, 2020): 479. http://dx.doi.org/10.3390/electronics9030479.
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Metal oxide semiconductor (MOS) capacitance within field effect transistors are of great interest in terahertz (THz) imaging, as they permit high-sensitivity, high-resolution detection of chemical species and images using integrated circuit technology. High-frequency detection based on MOS technology has long been justified using a mechanism described by the plasma wave detection theory. The present study introduces a new interpretation of this effect based on the self-mixing process that occurs in the field effect depletion region, rather than that within the channel of the transistor. The proposed model formulates the THz modulation mechanisms of the charge in the potential barrier below the oxide based on the hydrodynamic semiconductor equations solved for the small-signal approximation. This approach explains the occurrence of the self-mixing process, the detection capability of the structure and, in particular, its frequency dependence. The dependence of the rectified voltage on the bias gate voltage, substrate doping, and frequency is derived, offering a new explanation for several previous experimental results. Harmonic balance simulations are presented and compared with the model results, fully validating the model’s implementation. Thus, the proposed model substantially improves the current understanding of THz rectification in semiconductors and provides new tools for the design of detectors.
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Rajendran, Selvakumar, Arvind Chakrapani, Srihari Kannan, and Abdul Quaiyum Ansari. "A Research Perspective on CMOS Current Mirror Circuits: Configurations and Techniques." Recent Advances in Electrical & Electronic Engineering (Formerly Recent Patents on Electrical & Electronic Engineering) 14, no. 4 (June 17, 2021): 377–97. http://dx.doi.org/10.2174/2352096514666210127140831.
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Background: Immense growth in the field of VLSI technology is fuelled by its feasibility to realize analog circuits in μm and nm technology. The current mirror (CM) is a basic building block used to enhance performance characteristics by constructing complex analog/mixed-signal circuits like amplifier, data converters and voltage level converters. In addition, the current mirror finds diverse applications from biasing to current-mode signal processing. Methods: In this paper, the Complementary Metal Oxide Semiconductor (CMOS) technologybased current mirror (CM) circuits are discussed with their advantages and disadvantages accompanied by the performance analysis of different parameters. It also briefs various techniques which are employed for improvising the current mirror performance like gain boosting and bandwidth extension. Besides, this paper lists the CMs that use different types of MOS devices like Floating Gate MOS, Bulk-driven MOS, and Quasi-Floating Gate MOS. As a result, the paper performs a detailed review of CMOS Current mirrors and their techniques. Results: Basic CM circuits that can act as building blocks in the VLSI circuits are simulated using 0.25 μm, BSIM and Level 1 technology. In addition, various devices based CMs are investigated and compared. Conclusion: The comprehensive discussion shows that the current mirror plays a significant role in analog/mixed-signal circuits design to realize complex systems for low-power biomedical and wireless applications.
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Hossein-Babaei, Faramarz, and S. Masoumi. "Electrical Resistance and Seebeck Effect in Undoped Polycrystalline Zinc Oxide." Key Engineering Materials 605 (April 2014): 185–88. http://dx.doi.org/10.4028/www.scientific.net/kem.605.185.
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Thermoelectric properties of metal oxide semiconductors are of increasing interest in the field of sensors design and fabrication. The oxide components in the majority of such applications are polycrystalline in which the charge transportation is controlled both by the microstructure and the bulk properties of the material. While the dependence of the electrical resistivity on the microstructural and compositional changes in these materials is well understood, the complications encountered with their thermoelectric properties, have remained unattended. Here, we report experimental data on the Seebeck coefficient of undoped polycrystalline zinc oxide measured on the ceramic pellets fabricated by dry pressing of the powder and sintering at 800 and 1000°C, in air. Aluminum ohmic contacts are used for electrical connections. Seebeck voltage and electrical resistivity are measured at various temperatures and different atmospheric condition at the presence of predetermined temperature gradients.
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Stepenko, Serhii, Oleksandr Husev, Dmitri Vinnikov, Carlos Roncero-Clemente, Sergio Pires Pimentel, and Elena Santasheva. "Experimental Comparison of Two-Level Full-SiC and Three-Level Si–SiC Quasi-Z-Source Inverters for PV Applications." Energies 12, no. 13 (June 28, 2019): 2509. http://dx.doi.org/10.3390/en12132509.
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The paper presents a comparative study of two solar string inverters based on the Quasi-Z-Source (QZS) network. The first solution comprises a full-SiC two-level QZS inverter, while the second design was built based on a three-level neutral-point-clamped QZS inverter with Silicon based Metal–Oxide–Semiconductor Field-Effect Transistors (Si MOSFETs). Several criteria were taken into consideration: the size of passive elements, thermal design and size of heatsinks, voltage stress across semiconductors, and efficiency investigation. The Photovoltaic (PV)-string rated at 1.8 kW power was selected as a case study system. The advantages and drawbacks of both solutions are presented along with conclusions.
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Chandra Sekhar, S., Goli Nagaraju, Bhimanaboina Ramulu, and Jae Su Yu. "Rapid design of a core–shell-like metal hydroxide/oxide composite and activated carbon from biomass for high-performance supercapattery applications." Inorganic Chemistry Frontiers 6, no. 7 (2019): 1707–20. http://dx.doi.org/10.1039/c9qi00308h.
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Luciani, Giuseppina, Claudio Imparato, and Giuseppe Vitiello. "Photosensitive Hybrid Nanostructured Materials: The Big Challenges for Sunlight Capture." Catalysts 10, no. 1 (January 10, 2020): 103. http://dx.doi.org/10.3390/catal10010103.
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Solar radiation is becoming increasingly appreciated because of its influence on living matter and the feasibility of its application for a variety of purposes. It is an available and everlasting natural source of energy, rapidly gaining ground as a supplement and alternative to the nonrenewable energy feedstock. Actually, an increasing interest is involved in the development of efficient materials as the core of photocatalytic and photothermal processes, allowing solar energy harvesting and conversion for many technological applications, including hydrogen production, CO2 reduction, pollutants degradation, as well as organic syntheses. Particularly, photosensitive nanostructured hybrid materials synthesized coupling inorganic semiconductors with organic compounds, and polymers or carbon-based materials are attracting ever-growing research attention since their peculiar properties overcome several limitations of photocatalytic semiconductors through different approaches, including dye or charge transfer complex sensitization and heterostructures formation. The aim of this review was to describe the most promising recent advances in the field of hybrid nanostructured materials for sunlight capture and solar energy exploitation by photocatalytic processes. Beside diverse materials based on metal oxide semiconductors, emerging photoactive systems, such as metal-organic frameworks (MOFs) and hybrid perovskites, were discussed. Finally, future research opportunities and challenges associated with the design and development of highly efficient and cost-effective photosensitive nanomaterials for technological claims were outlined.
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Halliday, Cameron, and T. Alan Hatton. "The potential of molten metal oxide sorbents for carbon capture at high temperature: Conceptual design." Applied Energy 280 (December 2020): 116016. http://dx.doi.org/10.1016/j.apenergy.2020.116016.
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Kalagadda, B., N. Muthyala, and K. K. Korlapati. "Performance Comparison of Digital Circuits Using Subthreshold Leakage Power Reduction Techniques." Journal of Engineering Research [TJER] 14, no. 1 (March 1, 2017): 74. http://dx.doi.org/10.24200/tjer.vol14iss1pp74-84.
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Complementary metal-oxide semiconductors (CMOS), stack, sleep and sleepy keeper techniques are used to control sub-threshold leakage. These effective low-power digital circuit design approaches reduce the overall power dissipation. In this paper, the characteristics of inverter, twoinput negative-AND (NAND) gate, and half adder digital circuits were analyzed and compared in 45nm, 120nm, 180nm technology nodes by applying several leakage power reduction methodologies to conventional CMOS designs. The sleepy keeper technique when compared to other techniques dissipates less static power. The advantage of the sleepy keeper technique is mainly its ability to preserve the logic state of a digital circuit while reducing subthreshold leakage power dissipation.
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Nur-E-Alam, Lonsdale, Vasiliev, and Alameh. "Application-Specific Oxide-Based and Metal–Dielectric Thin-Film Materials Prepared by Radio Frequency Magnetron Sputtering." Materials 12, no. 20 (October 21, 2019): 3448. http://dx.doi.org/10.3390/ma12203448.
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We report on the development of several different thin-film functional material systems prepared by radio frequency (RF) magnetron sputtering at Edith Cowan University nanofabrication labs. While focusing on the RF sputtering process optimizations for new or the previously underexplored material compositions and multilayer structures, we disclose several unforeseen material properties and behaviours. Among these are an unconventional magnetic hysteresis loop with an intermediate saturation state observed in garnet trilayers, and an ultrasensitive magnetic switching behaviour in garnet-oxide composites (GOC). We also report on the unusually high thermal exposure stability observed in some nanoengineered metal–dielectric multilayers. We communicate research results related to the design, prototyping, and practical fabrication of high-performance magneto-optic (MO) materials, oxide-based sensor components, and heat regulation coatings for advanced construction and solar windows.
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Kusior, Anna, Milena Synowiec, Katarzyna Zakrzewska, and Marta Radecka. "Surface-Controlled Photocatalysis and Chemical Sensing of TiO2, α-Fe2O3, and Cu2O Nanocrystals." Crystals 9, no. 3 (March 20, 2019): 163. http://dx.doi.org/10.3390/cryst9030163.
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A relatively new approach to the design of photocatalytic and gas sensing materials is to use the shape-controlled nanocrystals with well-defined facets exposed to light or gas molecules. An abrupt increase in a number of papers on the synthesis and characterization of metal oxide semiconductors such as a TiO2, α-Fe2O3, Cu2O of low-dimensionality, applied to surface-controlled photocatalysis and gas sensing, has been recently observed. The aim of this paper is to review the work performed in this field of research. Here, the focus is on the mechanism and processes that affect the growth of nanocrystals, their morphological, electrical, and optical properties and finally their photocatalytic as well as gas sensing performance.
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Wang, Xiaochun, Meicheng Fu, Heng Yang, Jiali Liao, and Xiujian Li. "Temperature and Pulse-Energy Range Suitable for Femtosecond Pulse Transmission in Si Nanowire Waveguide." Applied Sciences 10, no. 23 (November 26, 2020): 8429. http://dx.doi.org/10.3390/app10238429.
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We experimentally measured the femtosecond pulse transmission through a silicon-on-insulator (SOI) nanowire waveguide under different temperatures and input pulse energy with a cross-correlation frequency-resolved optical gating (XFROG) measurement setup. The experimental results demonstrated that the temperature and pulse energy dependence of the Si photonic nanowire waveguide (SPNW) is interesting rather than just monotonous or linear, and that the suitable temperature and pulse-energy range is as suggested in this experiment, which will be valuable for analyzing the practical design of the operating regimes and the fine dispersion engineering of various ultrafast photonic applications based on the SPNWs. The research results will contribute to developing the SPNWs with photonic elements and networks compatible with mature complementary metal–oxide–semiconductors (CMOS).
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Pawar, B. G., P. P. Salvi, and S. S. Kolekar. "Electrochemical Tailoring of Honeycomb-Structured ZnO Thin Films by Interfacial Surfactant Templating." ISRN Nanomaterials 2012 (August 21, 2012): 1–6. http://dx.doi.org/10.5402/2012/907340.
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Zinc oxide thin films with honeycomb structures can be electrochemically produced by interfacial surfactant templating. Newly synthesized 4-amino-1-(2,3-dihydroxy propyl) pyridinium hydroxide ionic liquid exhibiting the hydroxyl functionalized ionic liquids (HFILs) was used in electrodeposition. This method utilizes amphiphile assemblies at the solid-liquid interface (i.e., the surface of a working electrode) as a template to gain the precisely tailor zinc oxide nanostructures. The results described here will provide a useful foundation to design and optimize greener protocol for the electrochemical construction of inorganic nanostructures thin films for possible application of films in nanotechnology field. Moreover, it is believed that this electrochemical tailoring approach can be extended to fabricate other porous metal oxide materials with a unique morphology or shape.
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Chang, Wen-Teng, Hsu-Jung Hsu, and Po-Heng Pao. "Vertical Field Emission Air-Channel Diodes and Transistors." Micromachines 10, no. 12 (December 6, 2019): 858. http://dx.doi.org/10.3390/mi10120858.
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Vacuum channel transistors are potential candidates for low-loss and high-speed electronic devices beyond complementary metal-oxide-semiconductors (CMOS). When the nanoscale transport distance is smaller than the mean free path (MFP) in atmospheric pressure, a transistor can work in air owing to the immunity of carrier collision. The nature of a vacuum channel allows devices to function in a high-temperature radiation environment. This research intended to investigate gate location in a vertical vacuum channel transistor. The influence of scattering under different ambient pressure levels was evaluated using a transport distance of about 60 nm, around the range of MFP in air. The finite element model suggests that gate electrodes should be near emitters in vertical vacuum channel transistors because the electrodes exhibit high-drive currents and low-subthreshold swings. The particle trajectory model indicates that collected electron flow (electric current) performs like a typical metal oxide semiconductor field effect-transistor (MOSFET), and that gate voltage plays a role in enhancing emission electrons. The results of the measurement on vertical diodes show that current and voltage under reduced pressure and filled with CO2 are different from those under atmospheric pressure. This result implies that this design can be used for gas and pressure sensing.
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Mizuno, Tomohisa, Naoki Mizoguchi, Kotaro Tanimoto, Tomoaki Yamauchi, Mitsuo Hasegawa, Toshiyuki Sameshima, and Tsutomu Tezuka. "New Source Heterojunction Structures with Relaxed/Strained Semiconductors for Quasi-Ballistic Complementary Metal–Oxide–Semiconductor Transistors: Relaxation Technique of Strained Substrates and Design of Sub-10 nm Devices." Japanese Journal of Applied Physics 49, no. 4 (April 20, 2010): 04DC13. http://dx.doi.org/10.1143/jjap.49.04dc13.
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Maset, Enrique, Juan Bta Ejea, Agustín Ferreres, José Luis Lizán, Jose Manuel Blanes, Esteban Sanchis-Kilders, and Ausias Garrigós. "Optimized Design of 1 MHz Intermediate Bus Converter Using GaN HEMT for Aerospace Applications." Energies 13, no. 24 (December 14, 2020): 6583. http://dx.doi.org/10.3390/en13246583.
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This paper presents the possibility of using Gallium Nitride (GaN) high-electron-mobility transistors (HEMTs) instead of the conventional silicon metal oxide semiconductor field effect transistor (MOSFET) to implement a high-frequency intermediate bus converter (IBC) as part of a typical distributed power architecture used in a space power application. The results show that processing the power at greater frequencies is possible with a reduction in mass and without impacting the system efficiency. The proposed solution was experimentally validated by the implementation of a 1 MHz zero-voltage and zero-current switching (ZVZCS) current-fed half-bridge converter with synchronous rectification compared with the same converter using silicon as the standard technology on power switches and working at 100 kHz. In conclusion, the replacement of silicon (Si) transistors by GaN HEMTs is feasible, and GaN HEMTs are promising next-generation devices in the power electronics field and can coexist with silicon semiconductors, mainly in some radiation-intensive environments, such as power space converters. The best physical properties of GaN HEMTs, such as inherent radiation hardness, low on resistance and parasitic capacitances, allow them to switch at higher frequencies with high efficiency achieving higher power density. We present an optimized design procedure to guaranty the zero-voltage switching condition that enables the power density to be increased without a penalization of the efficiency.
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Wise, Cross T. Asha, G. R. Suresh, M. Palanivelen, and S. Saraswathi. "Design of Pentacene-Based Organic Field-Effect Transistor for Low-Frequency Operational Transconductance Amplifier." Journal of Circuits, Systems and Computers 29, no. 11 (January 24, 2020): 2050181. http://dx.doi.org/10.1142/s0218126620501819.
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Mounting electronics circuits on a plastic flexible substrate are pertinent for biosensing applications due to their resilient nature, minimal processing conditions, lightweight and low cost. Organic Field-Effect Transistors (OFET)-based amplifier for flexible biosensors have been proposed in this paper. To design flexible biosensing circuits, Metal Oxide Semiconductor Field-Effect Transistor (MOSFET) with Polycyclic Hydrocarbon is a suitable choice. It is a big challenge to build an organic circuit using graphene electrode due to its poor performance of [Formula: see text]-type OFET, therefore it is advisable to use Pentacene as [Formula: see text]- and [Formula: see text]-type Organic semiconductors. Pentacene being one among the foremost totally investigated conjugated organic molecules with a high application potential because the hole mobility in OFETs goes up to 0.2[Formula: see text]cm2/(Vs), which exceeds that of amorphous silicon. In biosignal process, the first and most important step is to amplify the biosignal for further processing. Operational Transconductance Amplifier (OTA) plays an essential role in biological signal measuring instruments like EEG, ECG, EMG modules which measure the heart, muscle and brain activities. The OTA designed using this OFET is adaptable for flexible sensor circuits and also it derives the transconductance of 67 which is similar to silicon OTA. The amplifier designed here gives unit gain of 42[Formula: see text]dB with a frequency of 195[Formula: see text]Hz which is suitable for low-frequency biosignal processing applications.
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Zhang, Chunchun, Jixian Gong, Jianfei Zhang, Huiqin Li, and Nan Zhang. "Sound absorption of gradient structure fabrics based on functional finishing with metal compounds." Textile Research Journal 89, no. 19-20 (January 31, 2019): 3979–86. http://dx.doi.org/10.1177/0040517519826932.
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The common porous sound absorbing materials are thick and have a narrow sound absorption band. In order to design light and thin gradient structure functional fibrous assemblies with excellent performance of sound absorption and noise reduction, metal compounds with a heavy vibration damping characteristic were applied to a nonwoven by padding finishing, dipping finishing (DF) and spraying finishing. The influences of metal compound type, finishing method, the application amount of finishing agent and distribution of the finishing agent on nonwoven fabric for the sound absorption performance were studied. The results showed that the samples following DF had the largest amount of metal compound applied, and this processing method was beneficial to the construction of the gradient structure. The heavy vibration damping property of the metal compound could combine with the porous sound absorption mechanism of the nonwoven fabric to improve the sound absorption performance of fabric. The greater the amount of metal compound in the application, the better the sound absorption performance, and the effects of ferric oxide (Fe2O3) and barium sulfate (BaSO4) were particularly remarkable. Different finishing methods would affect the distribution of the metal compound on the material, which in turn affected the sound absorption performance.
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Sharma, Swati, and Marc Madou. "A new approach to gas sensing with nanotechnology." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 370, no. 1967 (May 28, 2012): 2448–73. http://dx.doi.org/10.1098/rsta.2011.0506.
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Nanosized gas sensor elements are potentially faster, require lower power, come with a lower limit of detection, operate at lower temperatures, obviate the need for expensive catalysts, are more heat shock resistant and might even come at a lower cost than their macro-counterparts. In the last two decades, there have been important developments in two key areas that might make this promise a reality. First is the development of a variety of very good performing nanostructured metal oxide semiconductors (MOSs), the most commonly used materials for gas sensing; and second are advances in very low power loss miniaturized heater elements. Advanced nano- or micro–nanogas sensors have attracted much attention owing to a variety of possible applications. In this article, we first discuss the mechanism underlying MOS-based gas sensor devices, then we describe the advances that have been made towards MOS nanostructured materials and the progress towards low-power nano- and microheaters. Finally, we attempt to design an ideal nanogas sensor by combining the best nanomaterial strategy with the best heater implementation. In this regard, we end with a discussion of a suspended carbon nanowire-based gas sensor design and the advantages it might offer compared with other more conventional gas sensor devices.
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Heyns, M., and W. Tsai. "Ultimate Scaling of CMOS Logic Devices with Ge and III–V Materials." MRS Bulletin 34, no. 7 (July 2009): 485–92. http://dx.doi.org/10.1557/mrs2009.136.
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AbstractOver the years, many new materials have been introduced in advanced complementary metal oxide semiconductor (CMOS) processes in order to continue the trend of reducing the gate length and increasing the performance of CMOS devices. This is clearly evidenced in the International Technology Roadmap for Semiconductors (ITRS), which indicates the requirements and technological challenges in the microelectronics industry in various technology nodes. Every new technology node, characterized by the minimal device dimensions that are used, has required innovations in new materials and transistor design. The introduction of deposited high-κ gate dielectrics and metal gates as replacements for the thermally grown SiO2 and poly-Si electrode was a major challenge that has been met in the transition toward the 32 nm technology node since it replaced the heart of the metal oxide semiconductor structure. For the next generation of technology nodes, even bigger hurdles will need to be overcome, since new device structures and high-mobility channel materials such as Ge and III–V compounds might be needed, according to the ITRS roadmap, to meet the power and performance specifications of the 16 nm CMOS node and beyond. The basic properties of these high-mobility channel materials and their impact on the device performance have to be fully understood to allow process integration and full-scale manufacturing. In addition to thermal stability, compatibility with other materials, electronic transport properties, and especially the passivation of electronically active defects at the interface with a high-κ dielectric, are enormous challenges. Many encouraging results have been obtained, but the stringent demands in terms of electrical performance and oxide thickness scaling needed for highly scaled CMOS devices are not yet fully met. Other areas where breakthroughs will be needed are the formation of low-resistivity contacts, especially on III–V materials, and III–V materials suited for pMOS channels. An overview of the major successes and remaining critical issues in the materials research on high-mobility channel materials for advanced CMOS devices is given in this issue of MRS Bulletin.
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Tian, Chengxiang, Juwei Wu, Zheng Ma, Bo Li, Pengcheng Li, Xiaotao Zu, and Xia Xiang. "Design and facile synthesis of defect-rich C-MoS2/rGO nanosheets for enhanced lithium–sulfur battery performance." Beilstein Journal of Nanotechnology 10 (November 14, 2019): 2251–60. http://dx.doi.org/10.3762/bjnano.10.217.
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We report a simple one-step hydrothermal strategy for the fabrication of a C-MoS2/rGO composite with both large surface area and high porosity for the use as advanced electrode material in lithium–sulfur batteries. Double modified defect-rich MoS2 nanosheets are successfully prepared by introducing reduced graphene oxide (rGO) and amorphous carbon. The conductibility of the cathodes can be improved through the combination of amorphous carbon and rGO, which could also limit the dissolution of polysulfides. After annealing at different temperatures, it is found that the C-MoS2/rGO-6-S composite annealed at 600 °C yields a noticeably enhanced performance of lithium–sulfur batteries, with a high specific capacity of 572 mAh·g−1 at 0.2C after 550 cycles, and 551 mAh·g−1 even at 2C, much better than that of MoS2-S nanosheets (249 mAh·g−1 and 149 mAh·g−1) and C-MoS2/rGO-S composites (334 mAh·g−1 and 382 mAh·g−1). Our intended electrode design protocol and annealing process may pave the way for the construction of other high-performance metal disulfide electrodes for electrochemical energy storage.
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ROY, BASUDEV, NIRMALYA GHOSH, PRASANTA K. PANIGRAHI, AYAN BANERJEE, ATHARVA SAHASRABUDHE, BIBUDHA PARASAR, and SOUMYAJIT ROY. "MICRO-OPTOMECHANICAL MOVEMENTS (MOMs) WITH SOFT OXOMETALATES (SOMs): CONTROLLED MOTION OF SINGLE SOFT OXOMETALATE PEAPODS USING EXOTIC OPTICAL POTENTIALS." Journal of Molecular and Engineering Materials 02, no. 01 (March 2014): 1440006. http://dx.doi.org/10.1142/s2251237314400061.
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An important challenge in the field of materials design and synthesis is to deliberately design mesoscopic objects starting from well-defined precursors and inducing directed movements in them to emulate biological processes. Recently, mesoscopic metal-oxide-based soft oxometalates (SOMs) have been synthesized from well-defined molecular precursors transcending the regime of translational periodicity. Here, we show that it is actually possible to controllably move such an asymmetric SOM, with the shape of a "peapod" along complex paths using tailor-made sophisticated optical potentials created by spin–orbit interaction of light due to a tightly focused linearly polarized Gaussian beam propagating through a stratified medium in an optical trap. We demonstrate motion of individual trapped SOMs along circular paths of more than 15 μm in a perfectly controlled manner by simply varying the input polarization of the trapping laser. Such controlled motion can have a wide range of applications starting from catalysis to the construction of dynamic mesoscopic architectures.
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Banerjee, Writam. "Challenges and Applications of Emerging Nonvolatile Memory Devices." Electronics 9, no. 6 (June 22, 2020): 1029. http://dx.doi.org/10.3390/electronics9061029.
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Emerging nonvolatile memory (eNVM) devices are pushing the limits of emerging applications beyond the scope of silicon-based complementary metal oxide semiconductors (CMOS). Among several alternatives, phase change memory, spin-transfer torque random access memory, and resistive random-access memory (RRAM) are major emerging technologies. This review explains all varieties of prototype and eNVM devices, their challenges, and their applications. A performance comparison shows that it is difficult to achieve a “universal memory” which can fulfill all requirements. Compared to other emerging alternative devices, RRAM technology is showing promise with its highly scalable, cost-effective, simple two-terminal structure, low-voltage and ultra-low-power operation capabilities, high-speed switching with high-endurance, long retention, and the possibility of three-dimensional integration for high-density applications. More precisely, this review explains the journey and device engineering of RRAM with various architectures. The challenges in different prototype and eNVM devices is disused with the conventional and novel application areas. Compare to other technologies, RRAM is the most promising approach which can be applicable as high-density memory, storage class memory, neuromorphic computing, and also in hardware security. In the post-CMOS era, a more efficient, intelligent, and secure computing system is possible to design with the help of eNVM devices.
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Ren, Xiaojiao, Ming Zhang, Nicolas Llaser, and Yiqi Zhuang. "On-Chip Measurement of Quality Factor Implemented in 0.35μm CMOS." Journal of Circuits, Systems and Computers 25, no. 08 (May 17, 2016): 1650087. http://dx.doi.org/10.1142/s0218126616500870.
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Based on time-domain quality factor (Q-factor) measurement principle, we have proposed an architecture which has the potential to be integrated on-chip. Thanks to the proposed original reconfigurable structure, the main measurement error from the offset of the operational transconductance amplifier (OTA) used can be cancelled automatically during the measurement operation, leading to a high accuracy Q-factor measurement. The digital control circuit plays an important role in the automatic passage between the two configurations designed, i.e., peak detector and comparator. The main advantages of the proposed time-domain Q-factor measurement lay on the possibility of being integrated next to the Micro Electro Mechanical System (MEMS) resonator to be measured, the miniaturization of the whole measuring system as well as the enhancement of the measurement performance, and to guide the design of such architecture, a theoretical analysis linking the required accuracy and the given Q-factor to the circuit parameters have been given in this paper. The proposed circuit is designed and simulated in a 0.35[Formula: see text][Formula: see text]m Complementary Metal Oxide Semiconductors (CMOS) technology. The post-layout simulation results show that the operating frequency can reach up to 200[Formula: see text]kHz with an accuracy of 0.4%.
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Kawamura, Yusuke, Shunsuke Hayashi, Yuya Shinde, and Takahide Oya. "Development of Paper Transistor Using Carbon-Nanotube-Composite Paper." Advances in Science and Technology 80 (September 2012): 59–64. http://dx.doi.org/10.4028/www.scientific.net/ast.80.59.
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We have developed a unique “paper transistor” comprised of carbon nanotube (CNT) composite papers. CNTs have recently attracted much research attention in the nanotechnology field due to their many excellent physical properties, including good electrical and heat conductivities, physical strength, and dual semiconducting- and metallic- characteristics. CNTs have great potential for use as many different functional materials. In a previous work, we developed a CNT-composite paper as a new functional material. A normal paper is flexible and can be fabricated and used easily, and we can easily fabricate the CNT-composite paper by mixing pulp with CNTs. The resulting CNT-composite paper has both CNT and normal paper characteristics. In this study, we focused primarily on the dual semiconducting- and metallic- characteristics exhibited by CNTs because we can create paper composites that are both semiconducting and metallic. Our main goal was to develop a field-effect-transistor (FET) using semiconducting- and metallic- CNT-composite papers. A conventional FET has metal, insulator, and semiconductor layers. Our FET also has three layers: the metallic CNT-composite paper is used for gate, source, and drain electrodes as the metal layer; the semiconducting CNT-composite paper is used for a semiconductor as the channel layer; and the normal paper is used as a gate insulator layer. The key point here is that we were able to design and develop an FET using only normal paper and two kinds of CNT-composite paper, without any silicon or semiconductors. After the construction, we measured the electrical conductivity of our FET to test its operation. A drain-to-source current of about 10μA was observed. Moreover, we could control the current flow by controlling the gate voltage. These results demonstrate that it is possible to fabricate a paper FET using only normal paper and two kinds of CNT-composite paper.
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Bjune, Caroline K., Thomas F. Marinis, and Yet-Ming Chiang. "Packaging Design and Assembly for Ultrahigh Energy Density Microbatteries." Journal of Microelectronics and Electronic Packaging 12, no. 3 (July 1, 2015): 129–38. http://dx.doi.org/10.4071/imaps.467.
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For commercially available lithium ion batteries, the package structures can account for as much as 70% of its volume. In a multiyear effort, we have developed designs, fabrications, and assembly processes for ultrahigh energy density microbatteries of 5 and 1 mm3. Over the course of the research, the packaging system evolved due to changes or limitation specific to the battery system itself. During the study, improvements in the construction of the housing for the cathodes were made. Anodized aluminum cans fabricated through our in-house micromachining facility replaced the electroformed gold cans used in earlier experiments. Throughout the iteration of the can design, a flange around its open end, which would be used for sealing, was present, and both designs were fabricated as arrays. The ability to fabricate the housings in an array format lends it to be implemented into a scalable production assembly process. Materials evaluated for the cover ranged from copper foil to the final design of metalized sapphire with a plated through via. One area which needed to be addressed was reducing the temperature of the assembly process due to a change in the cell materials. This resulted in developing a low-temperature hermetic sealing process. The seal between the cover and can was made using a novel composite ring of indium and epoxy. The indium provided the hermeticity needed for the battery chemistry and the epoxy provided mechanical robustness. Most of our experience was with sealing temperatures of 100°C, but the sealing temperature is only limited by the cure temperature of the epoxy. One experiment was conducted to look at the reliability of the seal. A dozen 1-mm3 cells were filled with lithium and sealed. They were aged in laboratory ambient environment and periodically weighed. There was no weight gain in any of the cells over the course of several months, but one cell that was opened at the end of the experiment rapidly gained weight as the lithium corroded. The microbattery cell developed in this program used a lithium cobalt oxide cathode in the form of a porous sintered compact. Its bottom surface was coated with a gold film so that it could be thermocompression bonded to a gold bump on the bottom of the can. Following bonding, the cathode assembly was spray coated with a polymer separator. The anode was a piece of lithium metal bonded to the battery cover. After the cover was sealed to the battery can, the cell was filled with electrolyte and charged. Then a plug was inserted in the via through the cover to seal the battery. Batteries assembled in this manner exhibited energy densities in excess of 200 Wh/L for the smaller volumetric package.
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Bjune, Caroline K., Thomas F. Marinis, and Yet-Ming Chiang. "Packaging Design and Assembly for Ultrahigh Energy Density Microbatteries." International Symposium on Microelectronics 2014, no. 1 (October 1, 2014): 000343–54. http://dx.doi.org/10.4071/isom-tp62.
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For commercially available lithium ion batteries, the package structures can accounts for as much as 70 percent of its volume. In a multi-year effort, we have developed designs, fabrications, and assembly processes for ultrahigh energy density micro batteries of 5 and 1 cubic millimeter. Over the course of the research, the packaging system evolved due to changes or limitation specific to the battery system itself. During the study, improvements in the construction of the housing for the cathodes were made. Anodized aluminum cans fabricated through our in-house micro-machining facility replaced the electroformed gold cans used in earlier experiments. Throughout the iteration of the can design, a flange around its open end, which would be used for sealing, was present, and both designs were fabricated as arrays. The ability to fabricate the housings in an array format lends it to be implemented into a scalable production assembly process. Materials evaluated for the cover ranged from copper foil to the final design of metalized sapphire with a plated though via. One area which needed to be addressed was reducing the temperature of the assembly process due to a change in the cell materials. This resulted in developing a low temperature hermetic sealing process. The seal between the cover and can was made using a novel composite ring of indium and epoxy. The indium provided the hermeticity needed for the battery chemistry and the epoxy provided mechanical robustness. Most of our experience was with sealing temperatures of 100°C, but the sealing temperature is only limited by the cure temperature of the epoxy. One experiment was conducted to look at the reliability of the seal. A dozen one cubic-millimeter cells were filled with lithium and sealed. They were aged in laboratory ambient environment and periodically weighed. There was no weight gain in any of the cells over the course of several months, but one cell which was opened at the end of the experiment rapidly gained weight as the lithium corroded. The micro-battery cell developed in this program used a lithium cobalt oxide cathode in the form of a porous sintered compact. Its bottom surface was coated with a gold film so that it could be thermocompression bonded to a gold bump on the bottom of the can. Following bonding, the cathode assembly was spray coated with a polymer separator. The anode was a piece of lithium metal bonded to the battery cover. After the cover was sealed to the battery can, the cell was filled with electrolyte and charged. Then a plug was inserted in the via through the cover to seal the battery. Batteries assembled in this manner exhibited energy densities in excess of 200 Wh/l for the smaller volumetric package.
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Allen, Norman S. "Book Review: Light Harvesting NanoMaterials, Bentham e-Books, ISBN: 978-1-60805-959-1; e-ISBN: 978-1-60805-958-4." Open Materials Science Journal 9, no. 1 (June 26, 2015): 49. http://dx.doi.org/10.2174/1874088x01509010049.
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Light Harvesting NanoMaterials, Bentham e-Books, ISBN: 978-1-60805-959-1;e- ISBN: 978-1-60805-958-4 Edited by Surya Prakash Singh The harvesting, capture and efficient conversion of solar light energy into electrical and heat energy through chemical and structural materials is now a rapid and exciting field of significant advancement and investigation in the scientific world. Many of these novel and often complex materials can attain important developments for many industrial outlets in energy transformation from solar power. This book targets a number of key newly developed nano-materials and consists in total of five chapters each one compiled by authors who are experts in that particular field and is edited by Surya Prakash Singh. The book consists of a number of important topics many developmental in the fields of organic/polymeric nano-materials which brings the reader up-to-date on many important features. The first chapter covers recent investigations covering the inter-locking and embedding of inorganic transistion metal compound based nano-particles onto solar panel surfaces as anti-reflective coatings in order to enhance light absorption characteristics for effective energy conversion. Silicon, titanium and silver compounds in various nano-formats are highlighted. Here the properties of the particles in harvesting light energy as a support and their photochemistry provides many important answers to questions in relation to the efficiencies of energy harnessing. The efficiencies of these processes is examined practically and theoretically in some depth with many very well illustrated devices. Silver nano-particles were particularly valuable and effective in this regard for enhancing solar energy absorption. Nano-crystalline titanium dioxide is a widely investigated material for solar energy harnessing but its inefficiency in absorption like many materials is a major deficiency. In chapter two, the use of doped titanias utilising tetrapyrolic sensitisers and various metal complexes for overcoming this problem is reviewed. Here, the deficiencies of usual ruthenium complexes is superseded via more effective porphyrins, phthalocyanines and corroles and with enhanced coupling i.e. via zinc significant energy conversions may be achieved. The next chapter explores the behavior and properties of polymeric materials as matrices for nano-composites where again energy efficiency conversion is crucial in determining the role of the light induced physic-chemicalprocesses. In this case the design of polymer based nanocomposites is widely assessed and is proving to be one of the most interesting and upcoming fields in solar energy harnessing. Of course, one major setback in this area with organo-materials is durability. In chapter four, one rather interesting area of growing interest in utilising solar energy is that dealing with gold and titania nanoparticles called “plasmonic photocatalysts”. This important field has direct relevance to photo-induced electrical and semiconductor processes aswell as significance in the manufacture of photoelectrochemical catalysts due to their broad visible absorption characteristics and hence high efficiency. In this context, the formulation and properties of the various catalysts can result in the production of novel highly active material complexes with high efficacy for oxidation of organic compounds. In the last chapter C60-based solar cells with copper oxides, CuInS2, phthalocyanines, diamond, porphyrin and exciton-diffusion blocking layers have been fabricated and characterized for use in energy efficient solar cell construction. High efficiencies are observed in all these devices when utilized with C60. To summarize, this important edited text provides the reader with a highly useful and valuable source of scientific information which focuses on many important aspects of development in light energy harvesting processes in both fields of photochemistry and photophysics thus providing many valuable ways forward for further scientific development for the future in solar energy conversion and photocatalysis. It makes interesting reading coupled with many new ideas and is very well illustrated and certainly provides a valuable reference source for chemists, physicists, biologists and engineers working in the field in both academia, government and industry, alike.
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Lo, Momath, Mahamadou Seydou, Asma Bensghaïer, Rémy Pires, Diariatou Gningue-Sall, Jean-Jacques Aaron, Zineb Mekhalif, Joseph Delhalle, and Mohamed M. Chehimi. "Polypyrrole-Wrapped Carbon Nanotube Composite Films Coated on Diazonium-Modified Flexible ITO Sheets for the Electroanalysis of Heavy Metal Ions." Sensors 20, no. 3 (January 21, 2020): 580. http://dx.doi.org/10.3390/s20030580.
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Highly sensitive multicomponent materials designed for the recognition of hazardous compounds request control over interfacial chemistry. The latter is a key parameter in the construction of the sensing (macro) molecular architectures. In this work, multi-walled carbon nanotubes (CNTs) were deposited on diazonium-modified, flexible indium tin oxide (ITO) electrodes prior to the electropolymerization of pyrrole. This three-step process, including diazonium electroreduction, the deposition of CNTs and electropolymerization, provided adhesively-bonded, polypyrrole-wrapped CNT composite coatings on aminophenyl-modified flexible ITO sheets. The aminophenyl (AP) groups were attached to ITO by electroreduction of the in-situ generated aminobenzenediazonium compound in aqueous, acidic medium. For the first time, polypyrrole (PPy) was electrodeposited in the presence of both benzenesulfonic acid (dopant) and ethylene glycol-bis(2-aminoethylether)-tetraacetic acid (EGTA), which acts as a chelator. The flexible electrodes were characterized by XPS, Raman and scanning electron microscopy (SEM), which provided strong supporting evidence for the wrapping of CNTs by the electrodeposited PPy. Indeed, the CNT average diameter increased from 18 ± 2.6 nm to 27 ± 4.8, 35.6 ± 5.9 and 175 ± 20.1 after 1, 5 and 10 of electropolymerization of pyrrole, respectively. The PPy/CNT/NH2-ITO films generated by this strategy exhibit significantly improved stability and higher conductivity compared to a similar PPy coating without any embedded CNTs, as assessed by from electrochemical impedance spectroscopy measurements. The potentiometric response was linear in the 10−8–3 × 10−7 mol L−1 Pb(II) concentration range, and the detection limit was 2.9 × 10−9 mol L−1 at S/N = 3. The EGTA was found to drastically improve selectivity for Pb(II) over Cu(II). To account for this improvement, the density functional theory (DFT) was employed to calculate the EGTA–metal ion interaction energy, which was found to be −374.6 and −116.4 kJ/mol for Pb(II) and Cu(II), respectively, considering solvation effects. This work demonstrates the power of a subtle combination of diazonium coupling agent, CNTs, chelators and conductive polymers to design high-performance electrochemical sensors for environmental applications.
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Fahad, Mohammed, and Bavanish B. "Tribological behavior of AZ91D magnesium alloy composite: effect of hybrid WC – SiO2 nanoparticles." Industrial Lubrication and Tribology 73, no. 5 (July 14, 2021): 789–95. http://dx.doi.org/10.1108/ilt-02-2021-0038.
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Purpose Aviation field requires a material with greater tribological characteristics to withstand the critical climate conditions. Hence, it is of paramount importance to enhance the wear resistance of material. AZ91D magnesium alloy is a light weight material used in the aviation field for the construction work. The purpose of this study is to augment the wear properties of AZ91D alloy by reinforcing with hard particles such as tungsten carbide (WC) and silicon dioxide (SiO2). Design/methodology/approach In this work, three types of composites were fabricated, namely, AZ91D – WC, AZ91D – SiO2 and AZ91D – (WC + SiO2) by ball milling method, and the tribological properties were analyzed using pin-on-disc apparatus. Findings Results showed that the hardness of AZ91D alloy was greatly improved due to the reinforcing effects of WC and SiO2 particles. Wear study showed that wear rate of AZ91D alloy and its composites increased with the increase of applied load due to ploughing effect and decreased with the increase of sliding speed owing to the formation of lubricating tribolayer. Further, the AZ91D – (WC + SiO2) composite exhibited the lower wear rate of 0.0017 mm3/m and minimum coefficient of friction of 0.33 at a load of 10 N and a sliding speed of 150 mm/s due to the inclusion of hybrid WC and SiO2 particles. Hence, the proposed AZ91D – (WC + SiO2) composite could be a suitable candidate to be used in the aviation applications. Originality/value This work is original which deals with the effect of hybrid particles, i.e. WC and SiO2 on the wear performance of the AZ91D magnesium alloy composites. The literature review showed that none of the studies focused on the reinforcement of AZ91D alloy by the combination of carbide and metal oxide particles as used in this investigation.
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Kotecki, Damian J. "Landmark Events in the Welding of Stainless Steels." Advanced Materials Research 794 (September 2013): 257–73. http://dx.doi.org/10.4028/www.scientific.net/amr.794.257.
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This lecture presents the authors personal views on the landmark events that have strongly affected the welding of stainless steels over their lifetime. Although 1913 is commonly recognized as the birth of stainless steels with the commercialization of the martensitic alloy of Harry Brearly and the austenitic alloy of Eduard Maurer and Benno Straus, the story can be considered to begin as long ago as 1797 with the discovery of chromium by Klaproth and Vauquelin, and the observation by Vauquelin in 1798 that chromium resists acids surprisingly well. From the 1870s onwards, corrosion resisting properties of iron-chromium alloys were known. One might mark the first iron-chromium-nickel constitution diagram of Maurer and Strauss in 1920 as a major landmark in the science of welding of stainless steels. Their diagram evolved until the outbreak of World War II in Europe in 1939, and nominally austenitic stainless steel weld metals, containing ferrite that provided crack resistance, were extensively employed for armor welding during the war, based on their diagram. Improved diagrams for use in weld filler metal design and dissimilar welding were developed by Schaeffler (1947-1949), DeLong (1956-1973) and the Welding Research Council (1988 and 1992). Until about 1970, there was a major cost difference between low carbon austenitic stainless steels and those austenitic stainless steels of 0.04% carbon and more because the low carbon grades had to be produced using expensive low carbon ferro-chromium. Welding caused heat affected zone sensitization of the higher carbon alloys, which meant that they had to be solution annealed and quenched to obtain good corrosion resistance. In 1955, Krivsky invented the argon-oxygen decarburization process for refining stainless steels, which allowed low carbon alloys to be produced using high carbon ferro-chromium. AOD became widely used by 1970 in the industrialized countries and the cost penalty for low carbon stainless steel grades virtually vanished, as did the need to anneal and quench stainless steel weldments. Widespread use of AOD refining of stainless steels brought with it an unexpected welding problem. Automatic welding procedures for orbital gas tungsten arc welding of stainless steel tubing for power plant construction had been in place for many years and provided 100% penetration welds consistently. However, during the 1970s, inconsistent penetration began to appear in such welds, and numerous researchers sought the cause. The 1982 publication of Heiple and Roper pinpointed the cause as a reversal of the surface tension gradient as a function of temperature on the weld pool surface when weld pool sulfur became very low. The AOD refining process was largely responsible for the very low sulfur base metals that resulted in incomplete penetration. The first duplex ferritic-austenitic stainless steel was developed in 1933 by Avesta in Sweden. Duplex stainless steels were long considered unweldable unless solution annealed, due to excessive ferrite in the weld heat-affected zone. However, in 1971, Joslyn Steel began introducing nitrogen into the AOD refining of stainless steels, and the duplex stainless steel producers noticed. Ogawa and Koseki in 1989 demonstrated the dramatic effect of nitrogen additions on enhanced weldability of duplex stainless steels, and these are widely welded today without the need to anneal. Although earlier commercial embodiments of small diameter gas-shielded flux cored stainless steel welding electrodes were produced, the 1982 patent of Godai and colleagues became the basis for widespread market acceptance of these electrodes from many producers. The key to the patent was addition of a small amount of bismuth oxide which resulted in very attractive slag detachment. Electrodes based on this patent quickly came to dominate the flux cored stainless steel market. Then a primary steam line, welded with these electrodes, ruptured unexpectedly in a Japanese power plant. Investigations published in 1997 by Nishimoto et al and Toyoda et al, among others, pinpointed the cause as about 200 ppm of bismuth retained in the weld metal which led to reheat cracking along grain boundaries where the Bi segregated. Bismuth-free electrode designs were quickly developed for high temperature service, while the bismuth-containing designs remain popular today for service not involving high temperatures.
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Li, Kai, Chao Teng, Shuang Wang, and Qianhao Min. "Recent Advances in TiO2-Based Heterojunctions for Photocatalytic CO2 Reduction With Water Oxidation: A Review." Frontiers in Chemistry 9 (April 15, 2021). http://dx.doi.org/10.3389/fchem.2021.637501.
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Photocatalytic conversion of CO2 into solar fuels has gained increasing attention due to its great potential for alleviating the energy and environmental crisis at the same time. The low-cost TiO2 with suitable band structure and high resistibility to light corrosion has proven to be very promising for photoreduction of CO2 using water as the source of electrons and protons. However, the narrow spectral response range (ultraviolet region only) as well as the rapid recombination of photo-induced electron-hole pairs within pristine TiO2 results in the low utilization of solar energy and limited photocatalytic efficiency. Besides, its low selectivity toward photoreduction products of CO2 should also be improved. Combination of TiO2 with other photoelectric active materials, such as metal oxide/sulfide semiconductors, metal nanoparticles and carbon-based nanostructures, for the construction of well-defined heterostructures can enhance the quantum efficiency significantly by promoting visible light adsorption, facilitating charge transfer and suppressing the recombination of charge carriers, resulting in the enhanced photocatalytic performance of the composite photocatalytic system. In addition, the adsorption and activation of CO2 on these heterojunctions are also promoted, therefore enhancing the turnover frequency (TOF) of CO2 molecules, so as to the improved selectivity of photoreduction products. This review focus on the recent advances of photocatalytic CO2 reduction via TiO2-based heterojunctions with water oxidation. The rational design, fabrication, photocatalytic performance and CO2 photoreduction mechanisms of typical TiO2-based heterojunctions, including semiconductor-semiconductor (S-S), semiconductor-metal (S-M), semiconductor-carbon group (S-C) and multicomponent heterojunction are reviewed and discussed. Moreover, the TiO2-based phase heterojunction and facet heterojunction are also summarized and analyzed. In the end, the current challenges and future prospects of the TiO2-based heterostructures for photoreduction of CO2 with high efficiency, even for practical application are discussed.
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Kajal and Vijay Kumar Sharma. "An Investigation for the Negative-Bias Temperature Instability Aware CMOS Logic." Micro and Nanosystems 13 (January 25, 2021). http://dx.doi.org/10.2174/1876402913666210125144339.
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Background: Scaling of the dimensions of semiconductor device plays a very important role in the advancement of very large-scale integration (VLSI) technology. There are many advantages of scaling in VLSI technology such as increment in the speed of the device and less area requirement of the device. Aggressive device scaling causes some limitations in the form of short channel effects which produce large leakage current. Large leakage current harms the characteristics of the device and affects the reliability of the device. Objective: The most important and popular reliability issue in deep submicron (DSM) regime is negative-bias temperature instability (NBTI). NBTI effect increases the threshold voltage of p-channel metal oxide semiconductor (PMOS) device over the time and affects the different characteristics of the device. As a result, circuit delay exceeds the design specification and there may be timing violations or logic failure. Different performance parameters are observed under NBTI effect for different logic gates. Methods: This paper presents an impact of NBTI at 22nm Berkeley short-channel IGFET model4 (BSIM4) predictive technology model (PTM) for complementary metal oxide semiconductor (CMOS) logic gates. Reliability simulations are utilised to evaluate the amount of gradual damage in PMOS device due to NBTI effect. Results : The impact of NBTI degradation is checked for various CMOS logic gates using Mentor Graphics’s Eldo circuit simulator. Output voltage and drain current are reducing over the time under NBTI effect. Conclusion: NBTI degradation increases the threshold voltage of PMOS device over the time and affects the different characteristics of the device.
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"The Mixed Logic Style based Low Power and High Speed 3-2 Compressor for ASIC designs at 32nm Technology." International Journal of Engineering and Advanced Technology 9, no. 1 (October 30, 2019): 43–49. http://dx.doi.org/10.35940/ijeat.a1027.109119.
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Compressors are the fundamental building blocks to construct Data Processing arithmetic units. A novel 3-2 Compressor is presented in this paper which is designed by Mixed logic design style. In addition to small size transistors and reduced transistor activity compared to conventional CMOS (Complementary Metal Oxide Semiconductor) gates, it provides the priority between the High logic and Low logic for the computation of the output. Various logic topologies are used to design the 3-2 compressor like High-Skew(Hi-Skew), Low-Skew(Li-Skew), TGL (Transmission Gate Logic) and DVL (Dual value Logic). This new approach gives the better operating speed, low power consumption compared to conventional logic design by reducing the transistors activity, improving the driving capability and reduced input capacitance with skew gates. Especially the Mixed logic style-3 provides 92.39% average power consumption and Propagation Delay of 99.59% at 0.8v. The H-SPICE simulation tool is used for construction and evaluation of compressor logic at different voltages. 32nm model file is used for MOS transistors
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"The Mixed Logic Style based Low Power and High Speed One-bit Binary adder for SOI Designs AT 32NM Technology." International Journal of Recent Technology and Engineering 8, no. 4 (November 30, 2019): 361–66. http://dx.doi.org/10.35940/ijrte.d6903.118419.
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Binary adders are the fundamental building blocks to construct Data Processing arithmetic units. A novel one-bit full adder is presented in this paper which is designed by Mixed logic design style. In addition to small size transistors and reduced transistor activity compared to conventional CMOS (Complementary Metal Oxide Semiconductor) gates, it provides the priority between the High logic and Low logic for the computation of the output. Various logic topologies are used to design the one-bit full adder like High-Skew(Hi-Skew), Low-Skew(Li-Skew), TGL (Transmission Gate Logic) and DVL (Dual Voltage Logic). This new approach gives the better operating speed, low power consumption compared to conventional logic design by reducing the transistors activity and by improving the driving capability. This Mixed logic style provides 83.53% average power consumption and Propagation Delay of 14.02% at 0.8v. The H-SPICE simulation tool is used for construction and evaluation of the Full adder logic at different voltages. The 32nm model file is used for MOS transistors
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Dargar, Abha, and Viranjay M. Srivastava. "Thickness Modeling of Short-Channel Cylindrical Surrounding Double-Gate MOSFET at Strong Inversion using Depletion Depth Analysis." Micro and Nanosystems 12 (August 31, 2020). http://dx.doi.org/10.2174/1876402912666200831175936.
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Aims: The semiconductor technology has a great impact on consistent growth in the Very-Large-Scale Integrated (VLSI) devices. The transistor size has been scaled down from micron to submicron and towards nanometer regime in past 30 years due to technological advancements. The most reliable solid state device is Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET) but this rapid decrease in the device dimensions the advent of Moore's law follows to several problems such as Short Channel Effects (SCE's) and Hot Carrier Effects. The channel becomes too small at short channel effects that necessitate analysis of the optimum device designs in particular in the operating conditions. The charge-sheet model that can quickly analyze a long-channel device current in the subthreshold to saturation regime without any discontinuity turns out to be inappropriate at reduced channel size. Objectives: At the nano-scaling of the device, since the accumulation layer thickness is comparable to the device, the assumption of the channel as a thin sheet of charge vanishes. Though the depletion layers or zone are the regions of the absentia of charges mostly, the existence affects the device behavior and the channel thickness. Therefore, channel thickness modeling becomes essential at various bias conditions to define the specifics of device operation and the channel dependence of the structural parameters. In this work the objective to develop analytical model and numerical analysis of the Cylindrical Surrounding Double-Gate (CSDG) MOSFET including the thickness derived based on formation of depletion depth to analyze the device performance at reducing dimensions. Methods: The analysis is built upon the device physical and electrical parameter such as capacitance, electric field, thickness, threshold voltage, effective channel dimensions, drain current are considered in this research. The depletion region in a MOSFET structure accounts the inclusion of the source and drain depletion regions divided primarily into three separate sub-regions as a junction between the diffused source/drain and the substrate, depletion under the channel and by region induced by lateral source and drain diffusion. The condition of a planar MOSFET in channel formation, i.e., for strong inversion, and when VGS > VTH have been considered for this mathematical analysis. Results: We have obtained the computed results of device thickness and depending parameters for a planar MOSFET and the CSDG MOSFET. Based on this analysis, the silicon thickness of the typical CSDG MOSFET computed is 180 nm, 281 nm, and 327 nm at VDS 0.2 V, 0.8 V, and 1.2 V, respectively. The achieved results through the thickness modeling proposed in this work show that nanoscale CSDG MOSFET can be deployed for the improvements in the device performance and novel design modifications. Conclusion: The analysis presented in this work significantly contributes to understanding the dependence of Semiconductor thickness in CSDG MOSFET and serve as a guide for future modifications in the structure for the device compactness.
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"Ion-selective field-effect transitors (ISFETs)." Philosophical Transactions of the Royal Society of London. B, Biological Sciences 316, no. 1176 (August 28, 1987): 31–46. http://dx.doi.org/10.1098/rstb.1987.0015.
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Most microelectronic chemical sensors are based on the insulated-gate field-effect transistor (IGFET), where the insulator-semiconductor is silicon dioxide-silicon, overlain by the ion-blocker, silicon nitride, and an additional layer conferring alternative ion-sensitivity and selectivity. Materials used to confer ion-sensitivity include, besides silicon nitride (H+), aluminium and tantalum oxides (H+), special glasses (H+, Na+, K+), valinomvcin (K+), tetraalkylammonium salts (Cl- , NOj), and various synthetic ionophores (Ca 2 +, Na+). The metal gate connection of the FET structure is replaced by a reference electrode in the solution containing the ion to be determined (analyte). The problems of design, construction and use of ion-selective FETS (ISFETS) as biosensors are surveyed and illustrated by work in Newcastle on ex vivo monitoring of blood during surgery for potassium and calcium ions and pH.
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Vayssieres, Lionel. "Hierarchical Design of Metal Oxide Multi-Dimensional Arrays from Solutions." MRS Proceedings 901 (2005). http://dx.doi.org/10.1557/proc-0901-rb17-01.
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AbstractThe hierarchical design of well-defined and highly oriented two- and three-dimensional arrays of conventional semiconductor nanomaterials and their large scale manufacturing at low cost remain a crucial challenge to unfold the very promising future of nanodevices. In addition to economical manufacturing of nanostructured semiconductors, better fundamental knowledge of their electronic structure, physical, interfacial and structural properties and stability, is required to fully exploit their fascinating potentials. To combine such essential requirements, the predictive creation of structurally well-defined and well-ordered functional and multi-functional materials is essential. As an attempt to achieve such ambitious goals, a novel strategy to thin film metal oxide semiconductor nanotechnology processing has been developed and investigated. A thermodynamic growth control concept based on the chemical and electrostatic minimization of the surface energy as well as a thin film growth technique have been developed. Such original approach allows the generation of nanomaterials with novel and functional morphologies. Advanced metal oxide nanostructures consisting of oriented multi-dimensional arrays featuring building blocks of controlled morphologies, sizes, aspect ratios and orientations at nano-, meso-, and microscale are genuinely fabricated directly onto various substrates of large physical areas without template, surfactant, undercoating or applied field from the hydrolysis-condensation of aqueous metal salts solutions at mild temperatures (below 100°C). A survey of the innovative advances in the fabrication of highly oriented and functional nanostructure arrays of transition and post-transition metal oxides are presented as well as one-dimensional confinement effects in purpose-built bundled iron oxide quantum rods.
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Naz, Syed Farah, Sadat Riyaz, and Vijay Kumar Sharma. "A Review of QCA Nanotechnology as an Alternate to CMOS." Current Nanoscience 17 (March 1, 2021). http://dx.doi.org/10.2174/1573413717666210301111822.
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Background: The human ken and understanding about esoteric phenomenon develops the period from space to the sub-atomic level. The passion to further explore the unexplored domains and dimensions boosts the human advancement in a cyclic way. A significant part of such passion follows in the electronics industry. Moore’s law is reaching the practical limitations because of further scaling of metal oxide semiconductor (MOS) devices. The need of a more dexterous and effective technology approach is demanded. Quantum-dot cellular automata (QCA) is an emerging technology which avoids the physical limitations of the MOS device. QCA is a dynamic computational transistor paradigm that addresses device density, power, operating frequency and interconnection problems. It requires an extensive study to know the fundamentals of logic implementation. Objective: Immense research and experiments due same vigor led to the evolving nanotechnology and a feasible alternative to complementary metal oxide semiconductor (CMOS) technology. A comprehensive study is presented in the paper to enhance the basics of QCA technology and the way of implementation of the logic circuits. Different existing circuits using QCA technology are discussed and compared for different parameters. Methods: Scaling the devices can reduce the power consumption of the MOS device. Quantum dots are nanostructures made from semi-conductive conventional materials. It is possible to model these constructions as 3-dimensional (3D) quantum energy wells. Logical operations and data movement are performed using Columbic interaction between nearby QCA cells instead of current flow. Results: The focus of this review paper is to study the trends which have been proposed and compared the designs for various digital circuits. The performance of different circuits such as XOR, adder, reversible gates and flip-flops are provided. Different logic circuits are compared on the parameters such as cell count, area and latency. At least 10 QCA cells are used for the XOR gate with 1 clock latency. Minimum 44 QCA cells are required to make a full adder with 1.25 clock latency.