In the last two decades, one-dimensional (1D) nanostructures have been extensively studied due to their distinguishing features such as quantum-mechanical confinement effects and high surface-to-volume ratios, exhibiting a number of potential applications. Of these, ZnO is one of the most interesting II-VI semiconductors with a wide direct bandgap of 3.37 eV and a high exciton binding energy...
For last 10 years, the performance of colloidal quantum dot-light-emitting diodes (QLEDs) has been dramatically improved. However, most of QLED work has been fulfilled in the form of monochromatic device, while white QLED still remains a long way to go. After solution-processed deposition of hole transport layer and emitting layer based on colloidal quantum dots, electron transport layer and...
Amorphous carbon (a-C) thin film applied to vacuum chambers of high-energy particle accelerators can decrease secondary electron yield（SEY）and suppress electron-cloud effectively. A dc magnetron sputtering apparatus to obtain a-C film has been designed. With the equipment, a-C thin film can be deposited on the inner face of stainless steel pipes ultimately which is uniform and high-quality....
Titanium-containing thin films are widely used in microelectronic device structures such as high-permittivity capacitors, barrier metals, and metal gate structures. ALD technology has replaced PVD and CVD to provide excellent step coverage, accurate film thickness control, and high film quality. Many titanium alkylamides and titanium alkoxides such as Tetrakis(dimethylamino)titanium (TDMAT)...
TiZrV film should be baked to make oxygen atom diffuse from the surface passivation layer into the interior of the film. Oxygen diffusion along grain boundary plays dominant role during activation. This process was simulated and the relation between activation temperature and grain size was obtained.
Copper nanoparticles (NP) have attracted great interest due to their unique properties which make them ideal candidates for applications in catalysis [1].
Within this study we have investigated the properties of nanoparticles produced in ionic liquid-aqueous micellar systems, which would provide a media for further coupling reactions.
Despite the protective stabilizing environment of the...
Fabrication of inorganic transparent conductive oxides (TCOs) on polymer substrates has been of increasing interest due to their potential applications in the field of flexible electronics. Nevertheless, the brittleness of inorganic thin films often results in a failure of the flexible electronic devices caused by strains formed during stretching, folding or bending. The higher the film...
A facile strategy to synthesize a composite composed of cubic Co3O4 nanocrystals anchored on chemically integrated g-C3N4-modified N-graphene (CN-NG) as an advanced anode material for high-performance lithium-ion batteries is reported. It is found that the morphology of the Co3O4 nanocrystals contains blunt-edge nanocubes with well-demarcated boundaries and numerous exposed low-index (111)...
Liquid helium cryopumps are among the most efficient high vacuum pumps used in controlled thermonuclear fusion experiments. Cryopumps can provide exceptionally high pumping capacity for hydrogen/deuterium at high pumping speed, but have limitations on the heat load. From the other side, growing average power of the fusion experiments demands high speed pumps capable to withstand high heat...
As a source material for numerous electrical applications, graphene has received great attention in two-dimensional (2D) materials field. For applications of graphene, it is critical to fine control of the Fermi level and the carrier concentration through a nondestructive doping method. Here, we develop an effective way to fabricate conformal ZnO thin films on graphene via atomic layer...
Visible-to-ultraviolet photodetectors are widely used in imaging, optical communication/interconnects/switches, security, and consumer optoelectronics. In contrast to conventional resistive-type photodetectors, thin-film transistor-based photodetectors (phototransistors) enable easier control of the responsivity and selectivity, which would allow increased amplification of lower detection...
Diamond-like carbon (DLC) films have been deposited on stainless steel wafers by plasma assisted chemical vapor deposition technique. Thickness and roughness of the film were measured by a surface profilometer. Microhardness, friction coefficient and profiles of wear tracks of DLC films were investigated by microhardness tester, ball on disk tribometer and surface profilometer, separately....
The five component CoCrFeNiCu films were deposited by DC magnetron sputtering using spark-melted targets at background pressure of 5×10−6 Pa with a deposition rate of ~10nm/min. The working pressure was 0.3 Pa by applying 99.9 % pure argon as sputtering gas. The films were deposited onto oxidized (100) Si wafers. The growth was carried out at room temperature as well as at 380 oC.
The...
Plasma nitrocarburizing is a thermochemical process that employs the pulsed DC luminescent discharge technology to introduce both nitrogen and carbon into the surfaces of metals and their alloys. The case formed by the treatment typically consists of two different layers: an thin outer layer, named compound layer, which presents excellent wear and tribological performances, and a thick inner...
Transparent semiconducting oxides, such as copper oxide, tin-doped indium oxide, fluorine-doped tin oxide, and zinc oxide (ZnO) have attracted considerable scientific attention owing to their unique properties. They are used in a wide variety of applications, including solar cells, surface-acoustic wave devices, and optoelectronic devices. ZnO which has a wide band gap (3.37 eV) and a high...
The combination of ALD and MLD techniques enables the fabrication of various functional organic – inorganic hybrid thin film structures. In this work, Al-doped zinc oxide (AZO) and zincone multi-layers were deposited on polymer substrate using diethylzinc (DEZ) with H2O and hydroquinone (HQ) precursors. Because the nanolaminates structure of AZO - zincone is consisted with organic and...
Among the dopants used for the ZnO TCO films, Ga have been one of the most potential candidates because its ionic radius is closed to Zn2+ that could cause only small ZnO lattice distortion even for high Ga concentrations. In addition, Ga is less reactive with oxygen compared with other impurities. B-doped ZnO also get widely investigation because it could perform perfect transparency and...
Next generation Si solar cell is heading for the use of ultra-thin Si wafers with the thickness less than 50µm. The challenge is to develop an effective light trapping technology for the PV cells in this category since crystalline Si is an indirect-gap material with a low optical absorption coefficient. In this work, we develop a novel device structure using an efficient light absorption layer...
Currently, a curved OLED(organic light-emitting diode) display is leading the smartphone market, so there is a growing interest in bendable displays. A transparent display has also attracted the attention of the smartphone market with the flexible display. To meet the required properties for the commercializing flexible and transparent display devices, the improvements of mechanical, optical...
Field emission induced lower switching power of TiO2 memristor using CNT-array as bottom electrode
Hamidreza Arab Bafrani1, Saeed Bagheri Shouraki2, Alireza Z Moshfegh*1, 3
1Institute for Nanoscience and Nanotechnology, Sharif University of Technology, Tehran, Iran
2Department of Electrical Engineering, Sharif University of Technology, Tehran, Iran
3Department of Physics, Sharif University...
The formation of coatings with high hardness, toughness, wear- and corrosion-resistance, suitable for applications in the area of medicine (anti-corrosion and wear-resistance coatings of different medical instruments, artificial joints and implants) and machine engineering (protective coatings on cutting, forming and petal processing instruments and bearings) are problems of great importance...
Organosilcate film such as polysilsesquioxanes can be used as a low dielectric material or an optical coating due to its low electron density, low dielectric constant and low refractive index. Also, they can be used as a base bottom layer to form nano-structure patterns using block copolymers. To make an aligned line patterns using block copolymers, it need to control surface energy of...
The Ti-Zr-V non-evaporable getter (NEG) films were grown on ion-implanted substrates, including aluminum, stainless steel, and CuCrZr alloy. To create buried disorder, Ar ions with an energy of 200 keV were implanted into the sample. The Ti-Zr-V getter films grown on these ion-implanted substrate were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), electron...
Controlling the charge transport by varying the molecular packing and understanding their structure−property correlations are essential for developing high-performance organic electronic devices.[1-3] Here, we demonstrate that the charge carrier mobility in organic single-crystal nanowires can be modulated with respect to the intermolecular center-to-center distance by applying uniaxial...
Stretchable electronic devices have received much attention due to its novel applications including stretchable, wearable displays, sensors, solar cells, light emitting skins, bio-metric devices, and human-interface devices. The development of transparent electrode is of importance to achieve high performance stretchable opto-electronics. ITO is the most widely used transparent electrodes in...
Die shrinks are essential for improving the productivity and performance of nanoscale semiconductor devices. Since the cost to manufacture a wafer is not proportional to the number of chips on the wafer, die shrinks reduce the manufacturing cost per chip by enabling the use of more chips on each wafer. As the chip size shrinks, it is possible to include many chips on the edge of the wafer....
Cu-Mn films are perspective contact and interconnect material [1]. However, their application on low-κ dielectrics (carbon doped oxides) is difficult since Mn can react with carbon extracting it from the dielectric and complicates interface chemistry. In this study we report in-situ TEM results obtained on thermal stability of metastable amorphous Cu-Mn films and solid phase reaction between...
The formation of an electron cloud is an issue that effects proton accelerators. It is a phenomena caused by electrons interacting with the surface of the walls of the accelerator resulting in the production of more electrons. It has already been seen that Laser Ablation Surface Engineering (LASE) of surfaces can reduce the Secondary Electron Yield (SEY) of Copper to below unity. In this work...
In recent, atmospheric microwave plasmas (AMP) have attracted much attention as promising plasma sources for industrial applications such as material processing, surface treatment and biomedicine [1]. The plasma sources have advantages: the AMP eliminates the need for a vacuum system and the AMP has a long operational time of the electrodes [2]. However, the AMP has its limitation to treat a...
Various multichannel rotating-element spectroscopic ellipsometers have excellent measurement capabilities, such as real-time, high-precision, non-destructive and non-contact, resulting in widespread use in semiconductor manufacturing processes. With the development of semiconductor device processing technology, thin films used in these techniques have become thinner and thinner, reaching the...
Microplasma arrays in atmospheric air for wide area have been developed. The plasma sources consist of quarter-wavelength resonators. Slot line resonators and coplanar waveguide resonators were used due to the compact size and simple structure [1]. The single resonator is capable of generating microplasmas with less than 5-W input power at resonance, and specific gas supply such as argon or...
In the present work, we have studied the magnetic properties of a ferrimagnetic mixed spins S=2 and S'=3/2 Ising thin film using Monte Carlo simulations. The ground state phase diagrams of mixed spins-Ising thin film are given. The different magnetic phases are found in different planes. The critical temperatures have been found for different values of thin films. The thermal magnetization...
The multiscale topography of Ti alloys (and especially Ti6Al4V) has been studied extensively as a way of conditioning cell adhesion and biocompatibility. In the present work, we have induced the modification of Ti alloys at the micro and nanoscale by using selective ion beam irradiation with Si ions at 5 MeV and wet etching in HF solutions. The selectivity is induced by the irradiation through...
Hefei advanced light source is the fourth generation Diffraction-Limited Storage Ring，which reduces aperture of vacuum chambers to few centimeters. General pumps cannot satisfy the ultrahigh vacuum due to conductance limitation and the intense photon bombardment. Most of the beam pipes need to be deposited with Ti-Zr-V nonevaporable getter (NEG) thin films in order to provide distributed...
As an II-VI semiconductor material, Cadmium zinc telluride (CdZnTe) compound which has wider band-gap and higher atomic number than Si, Ge and GaAs, is excellent for radiation application. CdZnTe-based devices are widely used in healthcare field, nuclear detection system, security checks and space science. Because of high cost and the difficulties of high quality CdZnTe single crystal growth,...
Amorphous oxide semiconductors (AOS) have attracted a great deal of attention as they offer a combination of interesting properties, namely high carrier mobility along with high optical transparency, mechanical flexibility as well as smooth surface. AOS are thus suitable for transparent flexible electronics such as thin-film transistors or/and flat-panel displays. Another key advantage is the...
Three-dimensional (3D) porous metal aerogels as a self-supporting proton structure show excellent ability to transmit protons. However, the reported metal porous aerogels are still in the field of electro-catalysis need to be further improved. In this study, we designed a simple method of hydrothermal reduction to prepare the hydrogel of 3D assembled metal nanowires, which obtain the metal...
The development of nanocomposite coatings has opened new possibilities for the fabrication of functional and protective coatings with unusual combinations of mechanical, tribological and chemical properties such as stability at elevated temperatures, high hardness and toughness, wear and corrosion resistance. In this study, nanolaminate structures consisting of ZrN and TiN layers were prepared...
Noise from refractive index (RI) fluctuations of the liquid environment near sensor surface due to factors such as temperature, pressure, and concertation gradient is inevitable in surface plasmon resonance (SPR) sensing technology. As a result, SPR devices are unable for quantitative and qualitative detection of small molecules and low-concentration analytes. To address this issue, novel...
The stabilization of tetragonal zirconium dioxide (zirconia) by doping at room temperature has already been carried out with dopant materials like Y or Mg. In the present work it was investigated if stabilization is possible with alternative dopants like Al and Cu. The films were produced with a dual cathode magnetron sputtering device. Because it is expected that the stabilization depends on...
The development of high-performance transparent electrodes is of great importance for efficient, low-cost organic optoelectronic devices such as organic solar cells and organic light emitting diodes. Silver Nanowires (AgNWs) are regarded as promising alternative transparent electrodes to replace conventional indium tin oxide (ITO) electrode due to their low sheet resistance, high...
It is well known that the stainless steel alloys are widely used to manufacture stainless steel (SS) implant and instruments for medical applications. However, they have low shear strength and wear resistance. The application of hard PVD coatings on properly prepared stainless steel surface could basically improve the mechanical and functional properties.
The substrate material used in the...
The effective synthesis two-dimensional molybdenum disulfides (2D MoS2) at low temperature is essential for their use in flexible devices. In this work, 2D MoS2 was grown directly at a low-temperature of 200 °C on both hard substrates (SiO2) and soft substrates (PI) using chemical vapor deposition (CVD) with Mo(CO)6 and H2S. We investigated the effect of the growth temperature and Mo...
Abstract
Visible-light-driven photocatalyst is an attractive research topic in the fields of pollution removal and fuel production. BiOBr has recently stimulated intensive interest in photocatalytic degradation because of its high photocatalytic activity and stability under UV and visible light irradiation. However, it is difficult to separate from liquid solution and its BET surface is needed...
The rGO-supported NiCo2O4 nanobelts (SPD-NiCo2O4/rGO) with surface pore defects and preferred orientation growth of the (311) plane are successfully constructed by a low-temperature hydrothermal method combined with a subsequent calcination treatment. The results show that as-obtained SPD-NiCo2O4/rGO nanoarchitectures possess abundant pore defects on the surface of NiCo2O4 nanobelts with an...
Abstract: A diamond on insulator structure with a pure tunnelling conduction between source and drain, modulated by a gate bias, is investigated as alternative nano-device. The Nothing On Insulator (NOI) cavity represents the main device body. The Atlas simulations establish superior drain currents and minimum capacitances suitable for THz operation.
Introduction: The NOI nano-device and the...
The exploration of highly active catalysts for hydrogen evolution reaction (HER) is beneficial to realize high catalytic activity and enhance kinetics for water splitting. Herein, the flower-like molybdenum disulfide/carbon nitride (MoS2/CN) nanosheets with thickness of 4.6 nm and enlarged interlayer spacing of 0.64 nm were synthesized via a facile hydrothermal method. As expected, the...
Thin film Kesterites (CZT(SSe)) are currently the most promising photovoltaics (PV) materials for new niche markets such as Building-integrated PV (BIPV) and Product-integrated PV (PIPV) due to their composition based on earth abundant elements and also to their promising photovoltaic device performance. Their tunable bandgap (between 1-1.5 eV) renders them particularly suited also for their...
