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Silicon Nanowire Field-Effect Transistors (SNWFETs) have emerged as promising candidates for advanced electronic devices due to their excellent electrostatic control, high carrier mobility, and scalability. The idea of the work is to investigate the drain current characteristics of SNWFETs by employing some selected dielectric materials, namely SiO2, ZrO2, and HfO2, to understand their impact on device performance. The electrical characteristic of these devices is systematically analyzed through extensive measurements, focusing on drain current behavior under different biasing conditions. The influence of SiO2, ZrO2, and HfO2 dielectrics on key performance metrics, such as subthreshold swing, on/off current ratio, and trans-conductor, is thoroughly investigate. Furthermore, the study explores the potential of ZrO2, and HfO2 as alternative dielectric materials to SiO2 for SNWFETS, considering their high dielectric constants and ability to provide effective gate control. The findings of this research shows that a 0.88 gate control parameter of SNWFET at room temperature can be made to perform better by using ZrO2, and HfO2 dielectric layer. Additionally, the room temperature of SNWFET with ZrO2 dielectric material has a higher drain current of 10.2 mA at a higher gate voltage of 0.6 volts when compared to other temperature curves. The presented results underscore the importance of the dielectric material selection in tailoring the electrical properties of SNWFETs for specific applications, paving the way for advancements in semiconductor technology. [ABSTRACT FROM AUTHOR]

In this paper, we report the systematic study of formation energy, electronic, and magnetic properties of Iron-doped Hydrogen-saturated Silicon Nanowire (Fe:H-SiNW) using the first principle density functional theory. The results were obtained by the generalized gradient approximation (GGA) approach and examined along (100) direction-oriented silicon nanowire with a diameter of 1nm. The results showed that H-SiNW is a nonmagnetic semiconductor, while Fe:H-SiNW is a ferromagnetic half-metal. This study revealed that H-SiNW doped by Fe impurity can form a new type of 100% spin-polarized material, which is potentially fascinating for nano-electronic and nano-spintronic devices. [ABSTRACT FROM AUTHOR]

In nanowire transistors, gate-induced drain leakage (GIDL) is a significant issue. In this paper, the GIDL phenomenon in nanowire GAAFETs and its mechanism are introduced, in nanowire GAAFET, longitudinal band-to-band tunneling (L-BTBT) is dominant in GIDL. The effects of nanowire diameter, nanowire shape, DP, overlap and underlap, gate length and temperature on GIDL current magnitude are also introduced, these process parameters and influencing factors have different effects on GIDL current and the optimal parameters for suppressing GIDL current can be found in a certain numerical range. Finally, the spacer design GAAFET, insulated ring-on-channel GAAFET, and Dual Metal (DM) Dielectric Engineered (DE) Gate All Around (GAA) MOSFETs are summarized. These optimized designs can reduce the L-BTBT to suppress the GIDL current in a variety of ways without affecting the transistor performance, and even improve the switching ratio and high frequency performance of the transistor, making the transistor more suitable for highly integrated high frequency circuits. [ABSTRACT FROM AUTHOR]

Anode design is a crucial factor for the further development of lithium-ion battery (LIB) technology, especially in terms of achieving high charging rate performance, as typically needed in electric vehicles (EV). In the present work, a unique battery test cell was designed and fabricated to study in-situ the mechanical behavior of the silicon nanowire electrode during electrochemical lithiation using synchrotron X-ray microdiffraction. Modelling of the nanostructured anode was also performed to provide further understanding of the in-situ findings. The combined approach provides further in-depth understanding of the evolution of the mechanics in the silicon nanowires (1D nanostructure) during operation of the battery, and furthermore shows the path for potentially enhancing the performance of the device. 3D nanostructures have been identified as the key to dramatically enhanced kinetics performance of LIB. However, existing fabrication methodologies for 3D nanostructures are inherently expensive – using advanced lithography techniques or other nanopatterning methodologies, as well as using additive manufacturing approaches. Electrospinning (as an integrated additive manufacturing methodology) may be used to produce low-cost 3D-printed fiber structures. This will pave the way to achieve the order of magnitude increase in battery kinetics as needed to realize the vision of the sustainable transportation. [ABSTRACT FROM AUTHOR]

An experimental study of the process of destruction of a horizontal layer of water on a silicon substrate heated by a laser beam from the bottom side was conducted. It was found that with an increase in the thickness of the water film, a higher temperature is required for the formation of a dry spot and, accordingly, a longer heating time. It was obtained that the maximum value of the speed of the contact line corresponds to the minimum size of the dry spot. With an increase in the thickness of the water film, the speed of the contact line decreases. [ABSTRACT FROM AUTHOR]

A comparison study on the optical properties of Silicon nanostructures have been done. Silicon nanostructures are fabricated by two methods: two-stage ion implantation and metal assisted chemical etching. In these methods, Ag ions for two-stage ion implantation and Ag metal as a catalyst for etching has been used. Optical properties of these Silicon nanostructures have been studied using different characterization techniques like Photoluminescence spectroscopy and Raman scattering. XRD measurements are carried out to see the crystallinity of the formed Silicon nanostructures. Surface morphology of etched samples have been studied extensively through SEM images. Etching time are varied and noted down at three different time i.e. 45 minutes, 60 minutes and 75 minutes. Interesting observation in this work is that after a threshold etching time, the formed Silicon nanowires start breaking up and micro-etching takes place with further increase in etching time. These observations are supported by Raman scattering, Photoluminescence results and SEM images. Optical properties of Silicon nanostructures formed in dual ion implantation and etching method (at 45 minutes sample) shows similar behavior. The details of the above are discussed in the presentation. [ABSTRACT FROM AUTHOR]

A hybrid model has been developed for calculating the flow of C2H2 gas in a cylindrical channel taking into account the mechanisms of heat exchange of gases with the surface and adsorption of molecules on the channel surface (molecular dynamics method and Monte Carlo method). A set of programs has been developed and calculations have been made of the deposition and / or scattering of acetylene molecules on the surface of a silicon substrate within the framework of the molecular dynamics method, taking into account the most accurate model of the atom-atom interaction of molecules with each other and with the substrate atoms. Combinations of the angle of incidence of acetylene on the substrate and the velocity of the center of mass of the molecule at which adsorption occurs are revealed. [ABSTRACT FROM AUTHOR]

The paper investigated on performance in charge sensing for substrate-gate integrated silicon nanowire field-effect transistor biosensor at different thickness of the buried oxide layer, sandwiched in between the top-silicon and substrate layers. The device structures with different buried oxide thickness ranging from 100 to 200 nm were designed and simulated using the Silvaco ATLAS device simulation software. The increase of buried oxide thickness reduced the strength of induced electric field that contributes to the formation of inversion layer for current flow through the silicon nanowire channel, hence contributed to the increase in threshold voltage. For simulation of charge sensing, the device demonstrated the ability to identify different interface charge values ranging from -5×1010 to -9×1010 e· cm−2 applied on the surface of the silicon nanowire channel to represent target charge biomolecules that bound to the biosensor in actual detection. Significant change in threshold voltage can be observed due to the applied interface charge density values and was evaluated to determine the sensitivity for charge sensing performance. The device shows better performance when designed with buried oxide thickness of 200 nm at sensitivity of 1.151 V/e· cm−2. [ABSTRACT FROM AUTHOR]

This paper reported on performance assessment of a field-effect transistor-based biosensor with different widths of the silicon nanowire transducer channel. Silvaco ATLAS device simulation software was used to model the device design with three different channel widths, which are 100, 150, and 200 nm. In this simulation, the bounded target biomolecules during actual detection using the biosensor were represented by several negative interface charge density values applied on the surface of the transducer channel. Increase in accumulation of hole carriers beneath the channel's surface was observed due to the availability of negative interface charges on the surface, hence increased the output drain current. Furthermore, width reduction of the device's channel had allowed more significant change in drain current due to application of different interface charge density values and increased the device's sensitivity. Among the simulated devices, silicon nanowire field-effect transistor-based biosensor with transducer channel width of 100 nm had shown highest sensitivity (-56.45 nA/e−cm2) with lowest interface charge density detection (2.79×1010e/cm-2), which means it enhances the interface charge detection by providing better response and allows lower limit of detection. Therefore, in actual detection, possibility for reaction of the transducer channel to the specific target biomolecule can be increased. [ABSTRACT FROM AUTHOR]

This work presents an experimental analysis of the substrate bias influence on the operation of Silicon Nanowire Field Effect Transistor (SiNW-FET). The device analysis has been performed by using atomic force microscope (AFM) and scanning electron microscope (SEM) to obtain the surface morphological characterization. Then, the electrical characterization was measured over a linear DC sweep, range from -1.5 V to 0.6 V with a step voltage of 0.01V and the variation on the substrate bias applied to the sample from -1V to 0V. As a result, the back gate was found to influence the conductivity of the nanowire with a higher than 0.79 V gate voltage to be applied. The device demonstrated a good behavior of p-type silicon nanowire field effect transistor and capable to operate as a biosensing device. [ABSTRACT FROM AUTHOR]

Electronic and mechanical properties of SiNWs were studied based on First principle method via density functional theory. Effect of orientations on mechanical properties of silicon nanowire were identified. The elastic properties of {110}, {100}, {011} and {111} orientations were calculated. Due to atomic interaction in wires, various mechanical properties of wire changes were noted. The results show for strain 0.1164×10−5, 0.12×10−5 and 0.115×10−5 with modulus of 149.6GPa, 75.5GPa and 85.1GPa respectively. [ABSTRACT FROM AUTHOR]

The study presented a functionalized silicon with (3-aminopropyl) triethoxysilane (APTES) to serve as a sensor for heavy metal detection. The amino-functionalized Si nanowires were tested against the heavy metal, lead (Pb). Due to the silicon electrochemical response towards the heavy metal ions, linear response to four different sources of water was observed. The results indicated that Pb can be detected with a high precision. Furthermore, confirmation was demonstrated using atomic absorption spectroscopy to determine the level lead content in the collected water source. Tab water (H2O), River H2O, Treated (H2O), DI (deionized) H2O and found the levels of 0.0859 mg/L, 0.0929 mg/L, 0.0052mg/L, 0.0023 mg/L with 5.8pA, 7.2pA, 4.6pA, 3.3pA current responses, respectively. Thus, with this high capability to discriminate water samples, the sensor potential can be employed for effective heavy metal detections and further be extended to a large sensor network in water treatment plant. A new microfluidic bonding material based on SU8 to implement electrical Nano chemical sensors for ions sensing, and an investigation of direct electrical measurement allowed for label free detection.. Thus, the study developed new room temperature bonding method using SU8 as an intermediate adhesive layer. The SU8 modified bonding was compared with non modified. The bond strength of SU8 modified was found to be stronger than ordinary plasma bonding under the same curing conditions. Overnight room temperature curing yields an average burst pressure of 420 kPa, which is more than adequate for many PDMS sensor devices. In contrast, non SU8 coated plasma bonded resulted in a burst pressure of only 174 KPa. [ABSTRACT FROM AUTHOR]

Nanowires (NWs) have many enhanced properties such as high yield strength, high ductility and large elongation under tensile loading. Though many molecular dynamics simulations have been performed exhibiting the benefit of having grain boundaries in nanowires, this study focuses on the mechanical properties of a specific grain formation similar to a structure of bamboo that indicates the opposite phenomena. In this experiment, BCC Fe nanowires were strained under tensile loading and with the assistance of molecular dynamics simulation it was demonstrated that the behavior of polycrystalline Fe NW exhibits dramatic differences from their single crystalline NW counterparts. In single crystalline Fe NW, dislocations were generated from the surface in the directions of specific planes for BCC materials; whereas in the case of nanowire with bamboolike polycrystalline shape, dislocation were generated from grain boundary due to the localized high stress and the heterogeneous character of atoms in the grain boundary. Ultimate strengths for 〈111〉, 〈1-1-2〉, 〈102〉 and 〈110〉 oriented single crystal NWs were found 34.57 GPa, 19.15 GPa, 14.94 GPa and 25.48 GPa respectively. A substantial low strength (8.89 GPa) was observed for the polycrystalline Fe structure, which was mainly caused due to the deformation in the interface of the two subsequent grains. Necking was observed followed by fracture, resulting in an overall drop in toughness. These findings can be a matter of concern in certain applications where materials with high strength and stability are required. [ABSTRACT FROM AUTHOR]

Understanding the operational behavior of nanoelectromechanical systems (NEMS) is the preliminary step to design functional sensors and actuators. Miniaturization is considered for further improvement in sensitivity, while the extreme surface area in NEMS devices plays a leading role in the effective performance through size dependence physical properties. Nanowire (NW) switches are one such device with significant surface effects present on the pull-in voltage. This study introduces a new approach to implement the surface effect into electromechanical behavior of NW switches based on finite element analysis. The influence of size and boundary condition on pull-in voltage is studied for silicon NWs. Results demonstrate the importance of length-to-thickness ratio as a suitable parameter to express the surface effect rather than the surface-area-to-volume ratio. [ABSTRACT FROM AUTHOR]

In this paper, the creation of a hybrid computer code based on the joint use of CUDA and MPI technology for silicon Si and silicon carbide SiC is considered in the framework of the molecular dynamics method. The efficiency of the created code is compared both with a program that uses only the MPI interface, and with a CUDA program designed to work only with one GPU. [ABSTRACT FROM AUTHOR]

In this paper, we present the synthesis of MoS2-CuO hetero-structure nanowire. The CuO nanowires were synthesized by thermal oxidation method, whereas the coating of MoS2 was done by chemical vapor deposition technique. The samples were characterized using Scanning Electron Microscope, Energy Dispersive Spectroscopy and Transmission Electron Microscope. The analysis shows the formation of the desired hetero-structure. [ABSTRACT FROM AUTHOR]

This paper presents a simple and fast non-lithographic method to make contacts on a single nanowire. The method involves growth of nanowires, segregation of the desired size nanowire, fabrication of micro-electrodes and placement and alignment of the nanowire on the micro-electrodes. The micro-electrodes were fabricated simply by a cutting tool of few micron thickness to provide a uniform channel of width 10-15 µm. The placement and alignment of the nanowire was obtained by the di-electrophoresis (DEP) method. The I-V characterization of a single CuO nanowire integrated by this method on a gold micro-electrode shows the usual Schottky behavior. Owing to its simplicity and cost advantage, the method has potential to be used as an alternative to lithography based method, for several applications such as gas sensors. [ABSTRACT FROM AUTHOR]

We report a novel and cost effective etching method to fabricate honey-comb metal nano template for the formation of well-aligned and well separated silicon nanowire arrays. The dewetting process is used at 300°C and 600°C to fabricate uniformly separated silver nanoparticles (AgNPs) on Si surface. The estimated mean diameter of AgNPs are about 60±20nm at both the dewettng temperatures. The surface roughness of AgNPs on Si are 243 nm and 356 nm for 300°C and 600°C respectively. The Ti/Au honey comb nano-template after removing the monolayer of AgNPs directly determines the diameter of silicon nanowires (SiNWs). These well-defined templates can be used to prepare vertically aligned SiNWs by using a conventional silver assisted electro less process. [ABSTRACT FROM AUTHOR]

Vertically aligned arrays of silicon nanowires (Si-NWs) have been fabricated via one-step, simple and cost-effective silver assisted chemical etching of crystalline Si-wafers at room temperature. A detailed study has been done on pursuing the growth characteristics of the Si-NWs prepared at different span of etching time. A linear relation has been established between the length of the nanowires and the etching period. Significant change in the reflectance spectra has been demonstrated leading to a gross reduction in the optical reflectance from ∼37% to less than 7%. In comparison with bulk c-Si, the Si-NW arrays with its elevated surface area facilitate efficiently absorbing light, while significantly reducing the reflection-loss; thereby, could favourably promote skilful light harvesting for photovoltaic applications. [ABSTRACT FROM AUTHOR]

Transparent thin-film heater (TTFH) is an important electronic device component requiring high transmittance material and a low sheet resistance with efficient energy conversion. In general, TTFH uses indium tin oxide, but it is brittle and unstable in acidic atmospheres, along with having a slow thermal response and high cost. This condition inspires the exploration of silver nanowires (Ag NWs) as a new material for transparent heater applications. In this study, Ag NWs were synthesized via a typical polyol synthesis process and deposited on glass substrates by using a spin coating method. The thermal annealing treatment was performed at 200 °C with three different time periods (10, 20 and 30 min) to enhance the performance of TTFH. The results show that the Ag NWs were successfully synthesized with a diameter of 40–50 nm with varying lengths of 5∼15 µm. The thermal annealing treatment of 10, 20 and 30 min produces agglomerates of Ag nanoparticles, decreases the length of Ag NWs and forms the nonconductive Ag2O phase. This causes a decrease of transmittance and sheet resistance, which results in a decrease of figure-of-merit (FoM) from 204 × 10−5 Ω−1 to 3 × 10−5 Ω−1. The thermal annealing process also caused the temperature of the TTFH to decrease from 76.7 °C to 31.8 °C within 200 s when a voltage of 20 V was applied. [ABSTRACT FROM AUTHOR]

Lithium Titanate, Li4Ti5O12 (LTO) is a promising candidate to be a lithium-ion battery anode. In this experiment LTO-ZnO/C are synthesized with hydrothermal method to form LTO nanowire and grinded with ZnO nanoparticle and graphite to form the composite. Three variables used are the different content of ZnO nanoparticle which are 4, 7 and 10 %, labeled as LTO-ZnO 4 %/C 5 %, LTO-ZnO 7 %/C 5 % dan LTO-ZnO 10 %/C 5 %. Characterization is done by XRD and SEM. Battery performance test is done by EIS, CV, and CD. The result of this research shows that in CV and CD testing LTO-ZnO 4 %/C 5 % perform best with working potential of 1.595 V and the best discharge vs C rate curve while from EIS testing we can see that LTO-ZnO 10 %/C 5 % has the lowest resistivity at 28.44 Ω. [ABSTRACT FROM AUTHOR]

The lattice thermal conductivity of silicon nanowires is reported on the basis of modified Callaway model. In the present formulation, the relaxation times of various participating processes have been evaluated in terms of lifetime (linewidths) via a comprehensive Hamiltonian which includes the contribution due to electrons, phonons, impurities, anharmonicities and interactions. The evaluation of lifetime is carried out by double-time temperature-dependent Green’s function theory. The frequency line widths are observed as an extremely sensitive quantity in the transport phenomena of the silicon nanowires, as it depends on a large number of scattering events, namely; combined boundary, impurity, phonon– phonon and interference scattering processes. It is observed in the present work that the lattice thermal conductivity of nanowires is much less than that of a bulk sample. This can be attributed due to the reduction of phonon group velocity and larger surface to volume ratio, which affect the mean free path of phonons and in turn cause the reduction in phonon conductivity. The present theoretical model makes a good agreement with experimental observation. [ABSTRACT FROM AUTHOR]

We have scrutinized structural and electronic properties of SiXC (X=4,5,6) nanowires having a variant shape of cross-section. Properties of studied nanowires were drastically changed in compare to bulk Si and C structure. The density of charge (DOS) revealed delocalized metallic bonding for studied NWs. Number of conduction channel is slightly increased with the nanowire become bigger. All the considered nanowires are behaved as a poor metallic or semi metallic rather than semiconductor and insulator in bulk Si and C respectively. [ABSTRACT FROM AUTHOR]

Features of heat transport in silicon-based porous structures with different morphology before and after thermal annealing are investigated. Specifically, fractal-like porous silicon and silicon nanowire arrays samples were considered. All the structures were annealed in dry air at various temperatures in diapason from 600 °C up to 1000 °C for 20 minutes. The photoacoustic technique with gas-microphone registration was applied for the thermal diffusivity evaluation of the samples. Particularly, the amplitude frequency dependencies of photoacoustic response from the considered samples in the classical gas-microphone configuration were measured in the range from 10 Hz to 3 kHz. The simulation of the experimental dependencies with the use of appropriate model allowed us to evaluate thermal conductivity. It was found that the short time thermal annealing together with increasing annealing temperature leads to significant reduction of thermal transport in mesoporous silicon. On the opposite, the thermal properties of silicon nanowires remain unaffected. [ABSTRACT FROM AUTHOR]

In Si nanowire (SiNW) solar cells enhanced light confinement property in addition to decoupling of charge carrier collection and light absorption directions plays a significant role to resolve the draw backs of bulk Si solar cells. In this report we have studied the dependence of the phovoltaic properties of Si NW array solar cells on the SiNW length and enhanced surface defect states as a result of enhanced surface area of the NWs. The SiNW arrays have been fabricated using metal catalyzed electroless etching (MCEE) technique. p-n junction has been produced by spin-ondopant technique followed by thermal diffusion process. Front and rear electrodes have been deposited by e-beam evaporation techniques. SiNW lengths have been controlled from ~ 320 nm to 6.4 μm by controlling the parameters of MCEE technique. Photovoltaic properties of the solar cells have been characterized by measuring quantum efficiency and photocurrent density vs. voltage characteristics. Morphological studies have been carried out by using scanning electron microscopy. Reduction in light trapping capability comes at the benefit of reduced surface defects. The reduction of surface defects has been proved to be more advantageous in comparison to the decrement of light trapping capability. The major contribution to the changes in cell efficiency comes from the enhancement of short circuit current density with a very weak dependence on open circuit voltage. This work is beneficial for the production of commercial Si solar cells where SiNW arrays could be used as an antireflection coating instead of using separate antireflection layers. Thus could reduced the production cost. [ABSTRACT FROM AUTHOR]

Silicon germanium nanowire has varieties of applications in nanoelectronics and optoelectronics due to technological advances. Nowadays, Computational Material Science is evolving because computer simulation is a tool to get insight about the properties of materials at atomic or molecular level which is used to predict and/or verify experiments. This is considered as a bridge between theory and experiment. In this paper, silicon germanium square nanowire having simulation length of 97.74 A0 is simulated by Nonequilibrium molecular dynamics simulation. Empirical interatomic potential used is Stillinger Weber potential. For canonical ensemble, effect of temperatures on thermal conductivity of silicon germanium square nanowire is studied [ABSTRACT FROM AUTHOR]

The structure of this review frames the discussion over three time periods; (1) the 4 decades since the mid-1970’s with the introduction and growth of Si-based ICs, first as bipolar and then MOS devices, focusing on the MOS scaling models developed by Robert Dennard at IBM, (2) a brief look at scaling issues for bulk planar CMOS in the late 2000’s, as limits of gate length shrinks became major problems and (3) an examination of channel length and width scaling for fully-depleted CMOS in the last decade. This note concludes with a mention of the challenges to further scaling presented by line-edge roughness and quantum confinement for the industry-standard form of bulk finFETs. [ABSTRACT FROM AUTHOR]

Recording bioelectric signals at high spatio-temporal resolution with low invasiveness is a major challenge in the field of bio-nanotechnology. Insofar, bioactive signals have been recorded with improved signal-to-noise ratio from cells in culture using arrays of nanopillars. However, production of such nanoscale electrodes is both time-consuming, pricey and might be only scarcely compatible with the Complementary Metal-Oxide-Semiconductor integrated circuits (CMOS-IC) technology. To take a step forward, we introduced an innovative approach to fabricate small, high-density Silicon NanoWires (SiNWs) with a fast, relatively inexpensive and low-temperature (200 °C) method. Growth of such SiNWs is compatible with ICs, thus theoretically allowing on-site amplification of bioelectric signals from living cells in tight contact. Here, we report our preliminary results showing biocompatibility and neutrality of SiNWs used as seeding substrate for cells in culture. With this technology, we aim to produce a compact device allowing on-site, synched and high signal/noise recordings of a large amounts of biological signals from networks of excitable cells (e.g. neurons) or from different areas of a single cell surface, thus providing super-resolved descriptions of bioelectric waveforms at the microdomain level. [ABSTRACT FROM AUTHOR]

The semiconductor nanowires have promising application in nanotechnology and nano devices. In this paper we have studied the effect of atomic order on the band structure in SiGe nanowires with 4 atoms containing 2 atoms of Si and 2 atoms of Ge. We have considered a structure with square and zigzag cross section. By this study we found that SiGe nanowires with a square cross section is a conductor while SiGe nanowires with zigzag cross section is a semiconductor and their indirect energy band gaps for zigzag A and zigzag B are 0.534 eV and 0.564 eV respectively. From the considered nanowires zigzag A nanowire has highest electronic and thermal conductivity while zigzag B nanowire has lowest electronic and thermal conductivity. [ABSTRACT FROM AUTHOR]

In this paper, we report the reflectance spectra of hydrogenated amorphous silicon nitride(a-SiNx:H) film grown on GaAs substrate using Plasma Enhanced Chemical Vapor Deposition (PECVD) technique. Fourier Transform Infrared (FTIR) spectroscopy has been used explicitly to resolve the LO and TO phonon mode contributions. The results of variable angle polarized IR reflectance on a-SiNx:H/GaAs samples are obtained for two different orientations. The calculated results for polarized reflectance are in good agreement with experimental measurements by choosing suitable frequencies and damping as fitting parameters. [ABSTRACT FROM AUTHOR]

One dimensional silicon based metallic heterostructure nanowires (NWs) have attracted a large attention due to its potential application as electron nano-connectors in silicon based nano-electronic devices. In the present work, we have considered Ni/Si core/shell nanowire, where Si shells are built around very thin Ni core. The negative binding energy value in NW shows its stability. We have studied electronic band structure of the nanowire, which shows metallic behavior due to major contribution of Ni-3d orbital. The quantum conductance is observed to be 5G0, which is in good agreement with zero bias transmission spectra of Ni/Si-NW. Furthermore, we have calculated IV-characteristics of the nanowire in range of -1.5V to 1.5V. The linear behavior upto ±1.0V shows ohmic characteristic of the core/shell nanowire. Highly magnitude of current value of 131.94 μA at 1.5 bias voltage and ohmic behavior attributes its possible application in nano-electronic devices as electron connector. [ABSTRACT FROM AUTHOR]

In the present paper, we have presented electronic and transport properties of silicon nanowire (SiNW) using density functional theory. Electronic and transport properties are computed for a different diameter of zigzag structure. These nanowires show metallic nature at a nano-scale. With increasing in diameter SiNWs are becoming more metallic. Out of 1R, 2R and 3R zigzag SiNWs, 1R zigzag serves a potential applicant as a electronic and thermal conducting material. [ABSTRACT FROM AUTHOR]

Silicon detectors have been widely used in high energy and nuclear physics experiments despite suffering severe radiation damage leading to degradationin the sensor performance. Such degradation include significant changes in detector efficiency, leakage current, bulk resistivity, space charge concentration, and free carrier trapping. In this work, neutron induced damages in siliconnanopillar detectors, the nanopillars dimensions being 10 nm diameter and 10 μm height wasanalyzed. The geometry was simulated in Geant4 and the nuclear interactions were evaluated by using ENDF/B-VII nuclear data library. Results showed that there are significant damages to the nano-pillars due to heavy charged particles and neutrons bombardment. Compared to the alpha (α) projectile, recoiled silicon produce more point defects with a higher yield. Neutrons also produce significant damage to the crystal lattice of Si nanopillars through point defects and it was also found that there is an increment in the production of 31P as the diameter of the nanopillar increases which further reduces the detector performance. The study demands optimization of pillar thickness for detection efficiency and damage. Hence with the detailed understanding of radiation effects on silicon devices combined with simulation techniques produces an impact on device design that predicts the behavior of specific devices when exposed to a radiation field of interest. [ABSTRACT FROM AUTHOR]

This paper focuses on the impact towards the performance of silicon nanowire field-effect transistor (SiNWFET) for biosensing application based on different channel lengths of the nanowire. A device numerical modelling tool, Silvaco ATLAS was used to design three p-type SiNW-FET biosensors with differentlengths of 0.5, 1.0, and 10.0 μm. The designed devices were simulated in order to observe and compare the effect of different channel length towards the electrical characteristic of the devices. Increase of the nanowire channel length had caused reduction of drain current, ID flowed through the channel from drain to source region. This is related to the increase of electrical resistance, R of the nanowire with the increase of nanowire length, L. In a way to study the effect of different channel lengths on the performance of the SiNW-FET biosensor, several negatively interfuce charge densities, QF (i.e. -0.1x1012, -0.5x 1012, and -1x1012 cm·2) were introduced on the surface of the SiNW channel to represent as the actual target deoxyribonucleic acid (DNA) captured by the bioreceptor of the biosensor. Based on the results, these negatively QF attracted the hole carriers below the surface of p-type nanowire to form an accumulation of charge carriers in the channel, causing an increase in the device output ID. Increase of the applied negative charge density had allowed for more ID to flow across the channel between drain and source region. The changes of ID with the applied Q F are utilized to determine the sensitivities and limit of detections (LOD) for all designed biosensor with different channel lengths. In comparison, the smallest nanowire length of 0.5 μm produced the highest sensitivity and lowest LOD of 2.17 μA/cm·2 and 7.85x 1010 cm·2, respectively, hence demonstrates better performance of SiNW-FET biosensor for the detection of specific charged DNA in analyte. [ABSTRACT FROM AUTHOR]

Reducing the thermal conductivity of silicon nanowires (SiNWs) can enhance the thermoelectric figure of merit. Applying non-equilibrium molecular dynamics (NEMD) simulation, it has been demonstrated that the thermal conductivity of SiNWs is approximately two orders of magnitude lower than bulk silicon crystal and that it can be reduced remarkably by including vacancy defects. It has been found that "surface vacancy defect" reduces thermal conductance much more than "center vacancy defect". The thermal conductivity reaches the minimum, which is about 17% of that of pristine SiNW, when 2% surface vacancy defect is introduced in the nanowire. In order to reveal the origin of this drastic reduction of thermal conductivity, the vibrational density of states (VDOS) analysis is performed and it has been found that due to the high surface to volume ratio, the various boundary inelastic scatterings of phonon reduce thermal conductivity significantly. Also, larger mass difference due to voids induces smaller thermal conductivity values. These results indicate that the inclusion of vacancy defects offers an available way for improving the thermoelectric performance of silicon nanowires. [ABSTRACT FROM AUTHOR]

We report an alternative approach to fabricate the vertically aligned aperiodic Si nanowire arrays by controlling the diameter of the Ag nanoparticles and tuneable ultrasonic removal. The process begins by sputtering the Ag thin film (t=5 nm) on the Si/SiO2 substrates. Followed by Ag thin film, annealed for various temperature (T=300°C, 400°C, 500°C and 600°C) to selectively achieve a high density, well-spaced and diameter controlled Ag nanoparticles (AgNPs) on the Si/SiO2 substrates. The sacrificial layer of AgNPs size indicates the controlled diameter of the Si nanowire arrays. Image J analysis for various annealed samples gives an indication of the high density, uniformity and equal distribution of closely packed AgNPs. Furthermore, the AgNPs covered with Au/Pd mesh (5 nm) as a template, was removed by ultrasonication in the etchant solution for several times in different intervals of preparation. The conventional and facile metal assisted electroless etching approach was finally employed to fabricate the vertically aperiodic sub-50 nm SiNWAs, can be applicable to various nanoscale opto-electronic applications. [ABSTRACT FROM AUTHOR]

We present a simple, quick and one-step methodology based on nano-second laser direct writing for the fabrication of micro-nanostructures on silicon surface. The fabricated surfaces suppress the optical reflection by multiple reflection due to light trapping effect to a much lower value than polished silicon surface. These textured surfaces offer high enhancement ability after gold nanoparticle deposition and then explored for Surface Enhanced Raman Scattering (SERS) for specific molecular detection. The effect of laser scanning line interval on optical reflection and SERS signal enhancement ability was also investigated. Our results indicate that low optical reflection substrates exhibit uniform SERS enhancement with enhancement factor of the order of 106. Furthermore, this methodology provide an alternative approach for cost-effective large area fabrication with good control over feature size. [ABSTRACT FROM AUTHOR]

Single nanowire electrode devices have their application in variety of fields which vary from information technology to solar energy. Silver nanowires, made in an aqueous chemical reduction process, can be reacted with gold salt to create bimetallic nanowires. Silver nanowire can be used as electrodes in batteries and have many other applications. In this paper we investigated structural and electronic transport properties of Ag nanowire using density functional theory (DFT) with SIESTA code. Electronic transport properties of Ag nanowire have been studied theoretically. First of all an optimized geometry for Ag nanowire is obtained using DFT calculations, and then the transport relations are obtained using NEGF approach. SIESTA and TranSIESTA simulation codes are used in the calculations respectively. The electrodes are chosen to be the same as the central region where transport is studied, eliminating current quantization effects due to contacts and focusing the electronic transport study to the intrinsic structure of the material. By varying chemical potential in the electrode regions, an I-V curve is traced which is in agreement with the predicted behavior. Bulk properties of Ag are in agreement with experimental values which make the study of electronic and transport properties in silver nanowires interesting because they are promising materials as bridging pieces in nanoelectronics. Transmission coefficient and V-I characteristic of Ag nano wire reveals that silver nanowire can be used as an electrode device. [ABSTRACT FROM AUTHOR]

The study proposed characterization and optimization of silicon nanosensor for specific detection of heavy metal. The sensor was fabricated in-house and conventional photolithography coupled with size reduction via dry etching process in an oxidation furnace. Prior to heavy metal heavy metal detection, the capability to aqueous sample was determined utilizing serial DI water at various. The sensor surface was surface modified with Organofunctional alkoxysilanes (3-aminopropyl) triethoxysilane (APTES) to create molecular binding chemistry. This has allowed interaction between heavy metals being measured and the sensor component resulting in increasing the current being measured. Due to its, excellent detection capabilities, this sensor was able to identify different group heavy metal species. The device was further integrated with sub-50μm for chemical delivery. [ABSTRACT FROM AUTHOR]

The nano structure based on silicon can be surface modified to be used as label-free biosensors that allow real-time measurements. The silicon nanowire surface was functionalized using 3- aminopropyltrimethoxysilane (APTES), which functions as a facilitator to immobilize biomolecules on the silicon nanowire surface. The process is simple, economical; this will pave the way for point-of-care applications. However, the surface modification and subsequent detection mechanism still not clear. Thus, study proposed step by step process of silicon nano surface modification and its possible in specific and selective target detection of Supra-genome 21 Mers Salmonella. The device captured the molecule with precisely; the approach took the advantages of strong binding chemistry created between APTES and biomolecule. The results indicated how modifications of the nanowires provide sensing capability with strong surface chemistries that can lead to specific and selective target detection. [ABSTRACT FROM AUTHOR]

Silicon is the most important material in semiconductor industry. As nano-devices shrink in size, the conventional understanding of electronic devices are no longer applicable as quantum effects start to play an important role for the behavior of the device. At the same time, when structures are approaching atomic scale, the precise fabrication by photo-lithographic techniques, for example, are not even applicable. Very often, the fabrication of regular structures rely on self-assembly is susceptible to fluctuations. Therefore, a deeper understanding to exploit the quantum behavior of nano-devices and precise control of building nano-structures are highly desired. Thus, genetic algorithm based on first principle analysis to optimize silicon nanowires electron and elastic properties is proposed. One nanometer (1nm) surface reconstruction by using genetic algorithm combined with ab-initio calculation is proposed. The SiNWs behavior to quasi-direct band gap transition with the decrease size and the band gap properties under different electrical voltage will be determined. [ABSTRACT FROM AUTHOR]

Arrays of silicon nanowires (SiNWs) of about 100 nm in diameter formed by metal-assisted chemical etching of crystalline silicon (c-Si) substrates were studied regarding efficiency of optical interactions in them. Strong scattering in the SiNW arrays results in enhanced photon lifetime in them, which was evidenced by measurement of the crosscorrelation function for femtosecond pulses scattered by the SiNW arrays. This effect results in an order of magnitude growth of efficiency such processes as spontaneous Raman scattering and third-harmonic (TH) generation compared to the signals for c-Si. Using (110) oriented c-Si substrate we managed to make well-oriented tilted SiNWs demonstrating strongly anisotropy of the TH and coherent anti-Stokes Raman scattering signals. In particular, efficiencies of these processes differ significantly when incident radiation propagates along or perpendicular to the SINWs. The obtained results could be explained by variations of the local fields in SiNWs and scattering cross-section. [ABSTRACT FROM AUTHOR]

Recently, CuO has attracted much interest owing to its suitable material properties, inexpensive fabrication cost and potential applications for optoelectronic devices. In this study, CuO thin films were deposited on glass substrates using chemical bath deposition technique and post-deposition annealing effect on the properties of the prepared samples were investigated. p-n heterojunction solar cells were then constructed by coating of p-type CuO films onto the vertically wellaligned n-type Si nanowires synthesized through MACE method. Photovoltaic performance of the fabricated devices were determined with current-voltage (I-V) measurements under AM 1.5 G illumination. The optimal short-circuit current density, open-circuit voltage, fill factor and power conversion efficiency were found to be 3.2 mA/cm-2, 337 mV, 37.9 and 0.45%, respectively. The observed performance clearly indicates that the investigated device structure could be a promising candidate for high-performance low-cost new-generation photovoltaic diodes. [ABSTRACT FROM AUTHOR]

Novel, highly sensitive Si-NWs with the length of 200ìm, with size of 15nm were fabricated using basic standard CMOS processes, Reactive ion etching (RIE) and Buffered Oxide Etching (BOE). FESEM micrograph was used to observe the defining and trimming results. With this process, the width of the wires is decreased from the initial, larger 1ìm dimensions to approximately 15nm in a controllable and convenient way. The device is pre-treated with higher pH DI for the mobile carriers to be accumulated at the inner surface of silicon nanowire and nine standard aqueous pH buffer solutions: pH2, pH3, pH 4, pH 5, pH6, pH8 and pH9 were used to test the electrical response of the device. The SiNWs sensor show the highest resistance value for pH 2 and the lowest resistance value for pH 9. In terms of sensitivity, the device with smaller nanowire is found to be more sensitive than larger nanowire as a result of the high surface-to-volume ratio and the measurements were done for 5 times on each sample in 24 hours after the nanowire sensor is immersed in DI water overnight (~24hours), the pH sensitivity is reproduced at every internal. This tendency is repeated in for all the samples. Hence, the fabricated device has demonstrated the potential device in the pH level detection. [ABSTRACT FROM AUTHOR]

The study presents an investigation into the effect of chitosan-CNT modification of silicon nanowire on DNA binding chemistry for the perfect attachment of ssDNA adhesion. MWCNT were purified through refluxing in concentrated HNO3 (V/V, 1:1) mixture for 2 hours at 55°C mixture of MWCNT-chitosan solution was prepared first immobilized on the Si surface. The surface was characterized by UV-vis measurement, Scanning Electrons microscope (SEM) and Fourier transform infrared spectroscopy (FTIRs) and series of electrical test were conducted to investigate the effect of MWCNT-chitosan concentration on the performance of the surface binding chemistry with Si-wire and chitosan-CNT modified. The results showed that the chitosan-CNT modification produced good probe adhesion and improve electrical properties. the took the advantage of CNTs with -COOH groups on silicon nanowire dispersed among chitosan containing -NH2 groups due to the peptide bonds formed between -COOH and -NH2 and due nanowire large surface area-to-volume ratio promises high sensitivity. We have established reliable procedure for the functionalization and is tapproach will allow a variety of species to be sensed on nanowire device. [ABSTRACT FROM AUTHOR]

We present the synthesis of functionalized-silicon nanowire (f-SiNWs) array which is currently an intense subject of research due to a wide range of opportunities for new generations of nanoscale electronic and optical devices. SiNW arrays were fabricated by a metal-assisted electrodeless wet chemical etching (MEWCE) of highly doped silicon (100) wafers. SiNWs are fabricated at different parameters like etching times, the concentration of chemicals, type of Si wafer, etc. Analysis of various deposition parameters has been carried out to optimize the growth of SiNW. The surface morphology of the etched Si wafer has been carried by electron microscopy. The origin of photoluminescence (PL) in SiNWs has been studied. Phonon confinement effect of functionalization has been analyzed by Raman spectroscopy and PL spectra. [ABSTRACT FROM AUTHOR]

This paper represents a channel length ratio optimization at a different high logic level voltage for 6-Silicon Nanowire Transistors (SiNWT) SRAM cell. This study is the first to demonstrate an optimized length ratio of nanowires with different Vdd of nano-scale SiNWT based SRAM cell. Noise margins (NM) and inflection voltage (Vinf) of transfer characteristics are used as limiting factors in this optimization. Results indicate that optimization depends on both length ratios of nanowires and logic voltage level (Vdd), and increasing of high logic voltage level of the SiNWT based SRAM cell tends to decrease in the optimized nanowires length ratio with decreasing in current and power. [ABSTRACT FROM AUTHOR]

A simple and low cost method to produce well aligned silicon nanowires at large areas using Ag-assisted chemical etching at room temperature were presented. The structure of silicon nanowires growth by metal-assisted chemical etching was observed. Prior to the etching, the silicon nanowires were prepared by electroless metal deposited (EMD) in solution containing hydrofluoric acid and hydrogen peroxide in Teflon vessel. The silver particle was deposited on substrate by immersion in hydrofluoric acid and silver nitrate solution for sixty second. The silicon nanowires were growth in different hydrogen peroxide concentration which are 0.3M, 0.4M, 0.5M and 0.6M and 0.7M.The influence of hydrogen peroxide concentration to the formation of silicon nanowires was studied. The morphological properties of silicon nanowires were investigated using field emission scanning electron microscopy (FESEM) and Energy Dispersive X-Ray Spectroscopy (EDS). [ABSTRACT FROM AUTHOR]

The lattice Thermal Conductivity for silicon nanofilm with a thickness of 20 and 100nm has been calculated theoretically over wide range of temperature. The modified Debye-Callaway model depending on the size dependence lattice volume and Debye temperature was used. In this calculation, both longitudinal and transverse modes are taken into account. Numerical results, predicate a significant decrease more than an order of magnitude of the lattice thermal conductivity for all thickness and it is due to the change of lattice volume, acoustic phonon confinement and roughness of boundary scattering. Theoretical results are in a good agreement with experimentally observed drop of the lattice thermal conductivity in silicon low dimensional structures. [ABSTRACT FROM AUTHOR]

Various analytical and numerical simulation models have been proposed in the past to solve the Boltzmann Transport Equation in order to describe semi-ballistic phonon transport in silicon nanowires. One of which is the statistical method called the Monte Carlo simulation. Most of the available Monte Carlo models however, prefer the inclusion of cuboidal boundary by applying equivalent diameter to bypass the complication of tracking phonon ensembles at the curved boundary. We propose a Monte Carlo simulation for transient phonon heat transport in silicon nanowires which includes the effect of a fully diffusive cylindrical boundary for temperatures ranging from 50K to 300K. A comparison between the simulation results obtained from the cuboidal and cylindrical boundary is provided to assess validity of the former assumption. The thermal conductivities obtained from the simulation compares well with the experimental data obtained from the literatures for silicon nanowires of diameters 115nm, 56nm and 37nm. [ABSTRACT FROM AUTHOR]