Search results for "LENI"
showing 10 items of 756 documents
Role of Nanoelectromechanical Switching in the Operation of Nanostructured Bi2Se3 Interlayers between Conductive Electrodes
2016
We demonstrate a simple low-cost method of preparation of layered devices for opto- and thermoelectric applications. The devices consist of a functional Bi2Se3 layer of randomly oriented nanoplates and flexible nanobelts enclosed between two flat indium tin oxide (ITO) electrodes. The number of functional interconnections between the ITO electrodes and correspondingly the efficiency of the device can be increased by gradual nanoelectromechanical (NEM) switching of flexible individual Bi2Se3 nanobelts in the circuit. NEM switching is achieved through applying an external voltage to the device. For the first time, we investigate in situ NEM switching and breakdown parameters of Bi2Se3 nanobel…
Parametrical study of multilayer structures for CIGS solar cells
2014
In this paper, a numerical analysis of relevant electrical parameters of multilayer structures for CIGS-based solar cells was carried out, employing the simulation software wxAMPS. In particular, we have focused on thin film cells having a ZnO:Al/ZnO/CdS/CIGS structure with a Molybdenum back contact. The aim of this work is to establish good theoretical reference values for an ongoing experimental activity, where our technology of choice is the single-step electrodeposition. In detail, we have analyzed how the main electrical properties change with the bang gap and the thickness of the absorber layer, for such a type of solar cell structure. Our results show that both efficiency and fill fa…
Influence of the parameters molecular structure and granularity on the compactibility of a powder
1995
Drug Dev. Ind. Pharm. ISI Document Delivery No.: RP128 Times Cited: 3 Cited Reference Count: 14 Andres, c ndiaye, a thomas, c tromelin, a chaillot, b pourcelot, y; International audience; The aim of this study was to determine whether it is possible to obtain better characterization of materials in order to find out if these one are suitable in Quality Assurance for direct tableting. We tried to show that a methodological approach combining chemical, physical and technological aspects could control the direct compression process. We chose orthoboric acid as a study model for the direct compression. From a chemical point of view, our findings show only one crystalline molecular structure (RX…
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.
Enhanced optical response of InSe nanosheet devices decorated with CsPbX3 (X = I, Br) perovskite nanocrystals
2021
Abstract The combination of several two-dimensional materials opens the door for the creation of cooperative nanodevices with functionalities that complement to each other and even compensate the weaknesses of the individual components. Two-dimensional indium selenide (InSe) shows one of the largest tunability bandgap found in two-dimensional materials with application in optoelectronics. However, the intrinsic out-of-plane luminescent dipolar nature limits its implementation in devices operating in vertical configuration. All-inorganic CsPbX3 (X = Br, I) cubic nanoparticles offer high absorption and emission quantum yields and great integrability with two-dimensional materials. Combining t…
Temperature Sensor Based on Colloidal Quantum Dots PMMA Nanocomposite Waveguides
2012
In this paper, integrated temperature sensors based on active nanocomposite planar waveguides are presented. The nanocomposites consist of cadmium selenide (CdSe) and cadmium telluride (CdTe) quantum dots (QDs) embedded in a polymethylmethacrylate (PMMA) matrix. When the samples are heated in a temperature range from 25$^{circ}{rm C}$ to 50 $^{circ}{rm C}$, the waveguided photoluminescence of QDs suffers from a strong intensity decrease, which is approximately quadratic dependent on temperature. Moreover, the wavelength peak of the waveguided emission spectrum of CdTe-PMMA shows a blue shift of 0.25 ${rm nm}/^{circ}{rm C}$, whereas it remains constant in the case of CdSe-PMMA. A temperature…
On the use of front-end cascode rectifiers based on normally on SiC JFET and Si MOSFET
2014
The new wide band-gap semiconductor devices provide new properties to be explored. Normally on silicon carbide (SiC) JFET power devices have several advantages, in particular low switching losses and the potential capabilities of high temperature and high reverse blocking voltage. Looking for improving the overall efficiency in power converters, new structures based on these power devices might be studied. In this paper, a cascode rectifier based on normally on SiC JFET is presented and analyzed. This rectification structure can be applied as front-end rectifier stage for ac-dc power converters, increasing the overall efficiency of these topologies. A second cascode rectifier based on silic…
Selenium adsorption on Mo(110): A first-principles investigation
2013
Selenium adsorption on molybdenum surfaces is a relevant process in the production of thin-film solar cells, in particular as far as the formation of the layered compound MoSe${}_{2}$ is concerned. In this paper we investigate the energetics of Se adsorption on the (110) surface of molybdenum using first-principles calculations in the two limiting cases of low and high coverage, and we establish a comparison with the more extensively investigated case of sulfur adsorption at submonolayer coverage. The studied system provides the opportunity for testing the most crucial approximations, namely, the choice of the exchange-correlation functional and the pseudopotential generation. We find that …
<title>Probing the interactions of single CdSe quantum dots with their local environment</title>
2001
The fluorescence blinking of single CdSe/ZnS nanocrystals under different experimental conditions is investigated. We show that the blinking process is very sensitive to the particle environment even if the nanocrystals are covered with a few monolayers of ZnS. Especially the presence of oxygen leads to a shortening of the on-times but leaves the off-times almost unaffected. Therefore, oxygen which is adsorbed to the surface might act as a scavenger for photo generated electrons and leaves the particle in its (positively charged) dark state.
Dendritic Mesoporous Silica Nanoparticles for pH-Stimuli-Responsive Drug Delivery of TNF-Alpha
2017
Tumor necrosis factor-alpha (TNF-α) is a pleiotropic immune stimulatory cytokine and natural endotoxin that can induce necrosis and regression in solid tumors. However, systemic administration of TNF-α is not feasible due to its short half-life and acute toxicity, preventing its widespread use in cancer treatment. Dendritic mesoporous silica nanoparticles (DMSN) are used coated with a pH-responsive block copolymer gate system combining charged hyperbranched polyethylenimine and nonionic hydrophilic polyethylenglycol to encapsulate TNF-α and deliver it into various cancer cell lines and dendritic cells. Half-maximal effective concentration (EC50 ) for loaded TNF-α is reduced by more than two…