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Graded Carrier Concentration Absorber Profile for High Efficiency CIGS Solar Cells

2015

We demonstrate an innovative CIGS-based solar cells model with a graded doping concentration absorber profile, capable of achieving high efficiency values. In detail, we start with an in-depth discussion concerning the parametrical study of conventional CIGS solar cells structures. We have used the wxAMPS software in order to numerically simulate cell electrical behaviour. By means of simulations, we have studied the variation of relevant physical and chemical parameters-characteristic of such devices-with changing energy gap and doping density of the absorber layer. Our results show that, in uniform CIGS cell, the efficiency, the open circuit voltage, and short circuit current heavily depe…

Transformation Algorithm of Dielectric Response in Time-Frequency Domain

2014

Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2014/547105 A transformation algorithm of dielectric response from time domain to frequency domain is presented. In order to shorten measuring time of low or ultralow frequency dielectric response characteristics, the transformation algorithm is used in this paper to transform the time domain relaxation current to frequency domain current for calculating the low frequency dielectric dissipation factor. In addition, it is shown from comparing the calculation results with actual test data that there is a coincidence for both results over a wide …

Effect of Nanodiamonds on Structure and Durability of Polyethylene Oxide-Based Nanocomposites

2016

Polymer-based nanocomposites containing nanodiamonds (NDs) are attractive multifunctional materials with a growing range of applications. In this work, in the frame of developing completely biocompatible systems, nanocomposites based on polyethylene oxide (PEO) and different amount of NDs have been formulated through melt mixing and fully characterized. In particular, the reinforcement effect of NDs in PEO has been probed through tensile tests, and the rheological response of PEO-based nanocomposites as a function of the nanoparticles amount has been investigated and discussed. The obtained results show that the presence of well-distributed NDs strengthens the mechanical performance of the …

Linear and Angular Distyrylpyrazines with Terminal Donor Groups: Synthesis, Solvatochromism, and Acidochromism of the Electronic Spectra

2011

A series of linear and angular distyrylpyrazines and lateral donor groups has been prepared by aldol condensation between dimethylpyrazines and the appropriate aromatic aldehyde. The optical absorption and emission properties of these systems were studied in different solvents and media. The materials display a strong solvatochromism of the emission that is reflected by large red shifts of their fluorescence emission maxima on increasing the solvent polarity. This behaviour suggests a highly polar emitting state, which is characteristic of compounds that undergo an internal charge transfer upon excitation. Upon protonation, the UV-vis spectra are altered, and the fluorescence intensity of t…

Thin-Film Photovoltaics 2013

2014

Thin-Film Photovoltaics 2011

2012

Thin-Film Photovoltaics 2014

2015

The interest toward alternative energy sources to fossil fuels (still the most convenient in terms of efficiency and cost) is current. Initiatives that seek to convert wind, geothermal energy, hydropower, marine, solar thermal energy, and photovoltaics or derived from biomass energy into other forms continue to involve several research groups. For example, the transfer from solar energy into electricity, which in turn can be used for water splitting and for the subsequent production of hydrogen, seems a major challenge to provide a sustainable contribution to the “Earth system” together with the realization of devices having high conversion efficiencies, low environmental impact, and low pr…

Assessment of root canal enlargement using Mtwo and BioRace rotary files.

2014

Objective. To evaluate root canal enlargement following mechanical shaping using 2 nickel titanium rotary systems.Material and Methods. Forty single-rooted teeth were immersed in resin and sectioned perpendicular to the long axis at 4, 8, and 12 mm from the apex. Digital capture of sections was performed before and after canal instrumentation using Mtwo and BioRace instruments. The area increase of endodontic space was calculated by subtraction.Results. The use of both instruments has allowed the removal of great amounts of dentin from the canal walls, even when the endodontic morphology is characterized by awkwardness to reach recesses.Conclusions. Both procedures seem to be valid and no d…

Relative Humidity Dependent Resistance Switching of Bi2S3Nanowires

2017

Electrical properties of Bi2S3nanowires grown using a single source precursor in anodic aluminum oxide templates are sensitive to the relative humidity in an inert gas environment. Dynamic sensing dependency is obtained and shows presence of spontaneous resistance switching effect between low and high relative humidity states. Employing the thermionic field emission theory, heights of Schottky barriers are estimated from the current-voltage characteristics and in relation to the humidity response. The change of Schottky barrier height is explained by local changes in physically adsorbed water molecules on the surface of the nanowire.

Preparation and Characterization of Inulin Coated Gold Nanoparticles for Selective Delivery of Doxorubicin to Breast Cancer Cells

2016

A novel folate-targeted gold-based nanosystem for achieving selectivity towards folate receptor FR positive cells is proposed, by virtue of the fact that the FR is a molecularly targeted entity overexpressed in a wide spectrum of solid tumors. A new inulin-folate derivative INU-FA has been synthesized to act as coating agent for 40 nm gold nanoparticles. The obtained polymer-coated gold nanoparticles [email protected] were characterized in terms of hydrodynamic radius, shape, zeta potential, and aqueous stability and were loaded with doxorubicin [email protected]/Doxo. Its release capability was tested in different release media. The selectivity of [email protected]/Doxo system towards FRs-…