Search results for " electrical properties"
showing 10 items of 13 documents
Electric conduction in solids: a pedagogical approach supported by laboratory measurements and computer modelling environments
2008
In this paper we present a pedagogic approach aimed at modeling electric conduction in semiconductors, built by using NetLogo, a programmable modeling environment for building and exploring multi‐agent systems. ‘Virtual experiments’ are implemented to confront predictions of different microscopic models with real measurements of electric properties of matter, such as resistivity. The relations between these electric properties and other physical variables, like temperature, are, then, analyzed.
Strain Sensing Coatings for Large Composite Structures Based on 2D MXene Nanoparticles
2021
Real-time strain monitoring of large composite structures such as wind turbine blades requires scalable, easily processable and lightweight sensors. In this study, a new type of strain-sensing coating based on 2D MXene nanoparticles was developed. A Ti3C2Tz MXene was prepared from Ti3AlC2 MAX phase using hydrochloric acid and lithium fluoride etching. Epoxy and glass fibre–reinforced composites were spray-coated using an MXene water solution. The morphology of the MXenes and the roughness of the substrate were characterised using optical microscopy and scanning electron microscopy. MXene coatings were first investigated under various ambient conditions. The coating experienced no sign…
Epoxy Resin/Carbon Black Composites Below the Percolation Threshold
2013
International audience; A set of epoxy resin composites filled with 0.25-2.0 wt.% of commercially available ENSACO carbon black (CB) of high and low surface area (CBH and CBL respectively) has been produced. The results of broadband dielectric spectroscopy of manufactured CB/epoxy below the percolation threshold in broad temperature (200 K to 450 K) and frequency (20 Hz to 1 MHz) ranges are reported. The dielectric properties of composites below the percolation threshold are mostly determined by alpha relaxation in pure polymer matrix. The glass transition temperature for CB/epoxy decreases in comparison with neat epoxy resin due to the extra free volume at the polymer-filler interface. At …
Photoconductivity and photovoltaic effect in indium selenide
1983
Transport and phototransport properties of crystalline indium monoselenide (InSe) doped with a variety of elements are reported. Measured mobilities, lifetimes, and effective diffusion lengths of photoexcited carriers are used to interpret electrical and photovoltaic properties of several different structures. These include p‐n junctions, bismuth/p‐type InSe, platinum/n‐type InSe, and indium tin oxyde (ITO)/p‐type InSe. External solar efficiencies of the best devices are between 5% and 6%. The influence on the efficiency of the various parameters is evaluated, and ways of improvement are discussed.
Nanocarbons in electrospun polymeric nanomats for tissue engineering: A review
2017
Electrospinning is a versatile process technology, exploited for the production of fibers with varying diameters, ranging from nano- to micro-scale, particularly useful for a wide range of applications. Among these, tissue engineering is particularly relevant to this technology since electrospun fibers offer topological structure features similar to the native extracellular matrix, thus providing an excellent environment for the growth of cells and tissues. Recently, nanocarbons have been emerging as promising fillers for biopolymeric nanofibrous scaffolds. In fact, they offer interesting physicochemical properties due to their small size, large surface area, high electrical conductivity an…
Multifunctional coordination polymers based on copper with modified nucleobases, easily modulated in size and conductivity.
2019
This Accepted Manuscript will be available for reuse under a CC BY-NC-ND licence after 24 months of embargo period
Electrical and photovoltaic properties of indium‐tin‐oxide/p‐InSe/Au solar cells
1987
Conditions for efficiency improvement and optimization in indium‐tin‐oxide/p‐indium‐selenide solar cells are discussed in this paper. This aim is achieved by using low‐resistivity p‐indium‐selenide and by incorporating a back‐surface‐field contact. This contact is insured by a p‐indium selenide/gold barrier whose rectifying behavior is explained through the complex impurity structure of p‐indium‐selenide. Electrical and photovoltaic properties of the cells are also reported. The efficiency parameters under AM1 simulated conditions have been improved up to 32 mA/cm2 for the short‐circuit current density, 0.58 V for the open‐circuit voltage, and 0.63 for the filling factor. As a result, solar…
Domain structure of epitaxial SrRuO3 thin films
2005
Growth of multidomains in epitaxial thin-film oxides is known to have a detrimental effect on some functional properties, and, thus, efforts are done to suppress them. It is commonly accepted that optimal properties of the metallic and ferromagnetic $\mathrm{SrRu}{\mathrm{O}}_{3}$ (SRO) epitaxies can only be obtained if vicinal $\mathrm{SrTi}{\mathrm{O}}_{3}$ (001) (STO) substrates are used. It is believed that this results from the suppression of multidomain structure in the SRO film. Here we revise this important issue. Nanometric films of SRO have been grown on STO(001) vicinal substrates with miscut $({\ensuremath{\theta}}_{V})$ angles in the $\ensuremath{\sim}0.04\ifmmode^\circ\else\te…
Blue lasing at room temperature in high quality factor GaN/AlInN microdisks with InGaN quantum wells
2007
The authors report on the achievement of optically pumped III-V nitride blue microdisk lasers operating at room temperature. Controlled wet chemical etching of an AlInN interlayer lattice matched to GaN allows forming inverted cone pedestals. Whispering gallery modes are observed in the photoluminescence spectra of InGaN/GaN quantum wells embedded in the GaN microdisks. Typical quality factors of several thousands are found (Q>4000). Laser action at similar to 420 nm is achieved under pulsed excitation at room temperature for a peak power density of 400 kW/cm(2). The lasing emission linewidth is down to 0.033 nm.
Novel method for functionalising and patterning textile composites:Liquid resin print
2016
Abstract The paper reports a novel method of integrating resin into continuous textile reinforcement. The method presents a print of liquid reactive resin into textile preforms. A series of targeted injections forms a patch which upon consolidation and curing transforms into a stiff region continuously spanning through preform thickness. Enhancing the injected resin with conductive phase allows creating a pattern of patches with controlled dimensions and added functionalities. Patterned composites reveal features which are not typical for conventional composites such as fibre bridged interfaces, regular thickness variation, and gradient matrix properties. The presented study explores the ro…