Search results for "Toe"
showing 10 items of 3824 documents
Influence of the Chemical Dissolution of MnS Inclusions on the Electrochemical Behavior of Stainless Steels
2005
Immersion of stainless steel containing a well-controlled density of MnS inclusions in 1 M NaCI, pH 3 leads to the chemical dissolution of these heterogeneities. This process was studied using in situ atomic force microscopy and the dissolution rate of MnS inclusions was estimated between 0.01 and 0.19 μm 3 /min. The effects of MnS dissolution on the chemical composition and the local electrochemical behavior of the specimen surface were investigated using secondary ion mass spectroscopy, X-ray photoemission spectroscopy, and the electrochemical microcell technique. It was shown that stable CrS and unstable FeSO 4 were formed. The size of the areas around MnS inclusions affected by the pres…
Synthesis and characterization of carbon coated sponge-like tin oxide (SnOx) films and their application as electrode materials in lithium-ion batter…
2016
Nanoporous metal oxides are widely used for the development of various functional nanostructures. We report on the synthesis of sponge-like tin oxide films on copper foil by anodization of electrochemically deposited tin films. The thin films are functionalized using a surface-anchoring carbon precursor-polymer (poly(acrylonitrile-b-dopamine acrylamide)) followed by annealing at elevated temperature to convert the polymer coating into a carbonaceous coating. The as prepared and the carbon coated films are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and Raman spectroscopy. Subsequently, both SnOx films are employed as a…
Pyranylidene indene-1,3-dione derivatives as an amorphous red electroluminescence material
2011
The organic light-emitting diode (OLED) has promising applications in flat-panel displays and novel light sources. Thus far, OLED structures have mostly been made by thermal evaporation in vacuum. An alternative approach is to use small molecules that form amorphous (glassy) structures from solutions. Such compounds can be used in ink-jet printing technologies and result in reduced OLED prices. We present an original red fluorescent organic compo- und 2-(2-(4-(bis(2-(trityloxy)ethyl)amino)styryl)-6-methyl-4H-pyran-4-ylidene)-1H-indene-1, 3(2H)-dione (ZWK1), and its derivative 2-(2,6-bis(4-(bis(2-(trityloxy)ethyl) amino)styryl)-4H- pyran-4-ylidene)-1H-indene-1,3(2H)-dione (ZWK2), where the m…
Low Current Density Driving Leads to Efficient, Bright and Stable Green Electroluminescence
2013
Electroluminescent devices have the potential to reshape lighting and display technologies by providing low-energy consuming solutions with great aesthetic features, such as flexibility and transparency. In particular, light-emitting electrochemical cells (LECs) are among the simplest electro-luminescent devices. The device operates with air-stable materials and the active layer can be resumed to an ionic phosphorescent emitter. As a consequence, LECs can be assembled using solution-process technologies, which could allow for low-cost and large-area lighting applications in the future. High efficiencies have been reported at rather low luminances (<50 cd m(-2)) and at very low current densi…
Vacuum-Deposited 2D/3D Perovskite Heterojunctions
2019
Low-dimensional (quasi-) 2D perovskites are being extensively studied in order to enhance the stability and the open-circuit voltage of perovskite solar cells. Up to now, thin 2D perovskite layers on the surface and/or at the grain boundaries of 3D perovskites have been deposited solely by solution processing, leading to unavoidable intermixing between the two phases. In this work, we report the fabrication of 2D/3D/2D perovskite heterostructures by dual-source vacuum deposition, with the aim of studying the interaction between the 3D and 2D phases as well as the charge transport properties of 2D perovskites in neat 2D/3D interfaces. Unlike what is normally observed in solution-processed 3D…
High efficiency single-junction semitransparent perovskite solar cells
2014
Semitransparent perovskite solar cells with a high power conversion efficiency (PCE) above 6% and 30% full device transparency have been achieved by implementing a thin perovskite layer and a simple foil compatible layout.
Memory effects in MOS capacitors with silicon quantum dots
2001
To form crystalline Si dots embedded in SiO2, we have deposited thin films of silicon-rich oxide (SRO) by plasma-enhanced chemical vapor deposition of SiH4 and O2. Then the materials have been annealed in N2 ambient at temperatures between 950°C and 1100°C. Under such processing, the supersaturation of Si in the amorphous SRO film produces the formation of crystalline Si dots embedded in SiO2. The narrow dot size distributions, analyzed by transmission electron microscopy, are characterized by average grain radii and standard deviations down to about 1 nm. The memory functions of such structures has been investigated in MOS capacitors with a SRO film sandwiched between two thin SiO2 layers …
MOCVD growth of TiO2 thin films on single crystal GaAs substrates
2000
Abstract TiO 2 thin films have been grown on (100)GaAs and (111)GaAs substrates by low-pressure metal organic chemical vapour deposition (LP-MOCVD). Titanium(IV) isopropoxide, Ti{OCH(CH 3 ) 2 } 4 , was used as a precursor and TiO 2 films were obtained without an additional oxygen flux. Scanning electron microscopy (SEM) experiments have shown a well ordered rod-like crystallisation in the films grown on (100)GaAs. This ordered crystallisation was favoured by a high deposition temperature ( T d =700°C). By contrast, no distinct order was observed in the films grown on (111)GaAs substrates. X-ray diffraction patterns revealed a mainly rutile structure for the TiO 2 films deposited on (100)GaA…
Corrosion behaviour of heavily deformed pearlitic and brass-coated pearlitic steels in sodium chloride solutions
2014
Abstract The influence of plastic deformation and galvanic coupling on the microstructure and corrosion behaviour of pearlitic steel and brass-coated pearlitic steel was investigated in sodium chloride solution at 25 °C. Microstructural changes were quantified using scanning electron microscopy coupled with EBSD. Chemical and electrochemical modifications were evaluated using XPS, ZRA, the electrochemical microcell technique and the weight loss method. From these experiments, the influence of microstructural changes on the electrochemical parameters and the corrosion rate was discussed.
Improved Cu2O/AZO Heterojunction by Inserting a Thin ZnO Interlayer Grown by Pulsed Laser Deposition
2019
Cu2O/ZnO:Al (AZO) and Cu2O/ZnO/AZO heterojunctions have been deposited on glass substrates by a unique three-step pulsed laser deposition process. The structural, optical, and electrical properties of the oxide films were investigated before their implementation in the final device. X-ray diffraction analysis indicated that the materials were highly crystallized along the c-axis. All films were highly transparent in the visible region with enhanced electrical properties. Atomic force and scanning electron microscopies showed that the insertion of a ZnO layer between the Cu2O and AZO films in the heterojunction enhanced the average grain size and surface roughness. The heterojunctions exhibi…