Search results for "THIN-FILM"

Influence of applied strain on the microstructural corrosion of AlMg2 as-cast aluminium alloy in sodium chloride solution

2012

International audience; The corrosion behavior of ISO AlMg2 (AA5052) was studied at the microscale using the Electrochemical Microcell Technique. The influence of plastic deformation on the corrosion resistance of this alloy was also examined. After polishing, pitting at small copper-enriched precipitates and structural etching were observed. After deformation, numerous slip bands were found in grains. After 5.5% plastic strain, the global electrochemical behavior of samples was significantly affected. Pitting potential was decreased in sites containing slip bands or in sites with large strain gradients (measured using microgauges deposited by lithography).

Light absorption and electrical transport in Si:O alloys for photovoltaics

2010

Thin films (100-500 nm) of the Si:O alloy have been systematically characterized in the optical absorption and electrical transport behavior, by varying the Si content from 43 up to 100 at. %. Magnetron sputtering or plasma enhanced chemical vapor deposition have been used for the Si:O alloy deposition, followed by annealing up to 1250 °C. Boron implantation (30 keV, 3-30× 1014 B/cm2) on selected samples was performed to vary the electrical sheet resistance measured by the four-point collinear probe method. Transmittance and reflectance spectra have been extracted and combined to estimate the absorption spectra and the optical band gap, by means of the Tauc analysis. Raman spectroscopy was …

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…

A Very Low Band Gap Diketopyrrolopyrrole-Porphyrin Conjugated Polymer

2017

International audience; A porphyrin-diketopyrrolopyrrole-containing polymer (poly(porphyrin-diketopyrrolopyrrole) (PPDPP)) shows impressive molar absorption coefficients from lambda=300 to 1000 nm. The photophysical and structural properties of PPDPP have been studied. With PPDPP as the electron donor and [ 6,6]phenyl C-71 butyric acid methyl ester (PC71BM) as the electron acceptor, the bulk heterojunction polymer solar cell showed overall power conversion efficiencies of 4.18 and 6.44% for as-cast and two-step annealing processed PPDPP: PC71BM (1: 2) active layers, respectively. These results are quite impressive for porphyrin-containing polymers, especially when directly included in the p…

Random Structural Modification of a Low-Band-Gap BODIPY-Based Polymer

2017

International audience; A BODIPY thiophene polymer modified by extending conjugation of the BODIPY chromophore is reported. This modification induces tunability of energy levels and therefore absorption wavelengths in order to target lower energies.

Thin-Film Transistors: Two-Step Solution-Processed Two-Component Bilayer Phthalocyaninato Copper-Based Heterojunctions with Interesting Ambipolar Org…

2016

MATERIALS AND PROCESSING ISSUES FOR THE MANUFACTURING OF INTEGRATED PASSIVE AND ACTIVE DEVICES ON FLEXIBLE SUBSTRATES

2008

Plast_ICs is a Public/Private Laboratory funded by Italian Government aimed to build a novel technological platform for the development of flexible electronics, mainly, but not solely, based on thin inorganic films. Integration of different functions, on single and/or multiple plastic foils, to generate a smart system is the final goal of the project. The building blocks of the platform will be presented, starting from the different plastic substrates characterization, going through the development of active devices, such as thin-film- transistors, and passive devices, like thin-film- resistors, capacitors, inductors. Fully inorganic elementary devices, based on optical patterning and in va…

Thin Film Metal Oxides for Displays and Other Optoelectronic Applications

2020

Thin films of metal oxides have been extensively studied for various applications because of their durability, lower cost and lower toxicity, excellent chemical, magnetic, electrical and optical properties. A fusion of electrical and optical properties led to the growth of optoelectronic devices for a variety of applications including displays, light-emitting diodes, photovoltaic cells, photodetectors, optical storage, medicine, and so on. Optoelectronic devices have revolutionized our daily lives with their potentials in various aspects. An extensive research on materials for these devices has to be credited for the improvement in their performance over the years. Several metal oxide thin …

Ultra-thin film sensors based on porphyrin-5-ylphosphonate diesters for selective and sensitive dual-channel optical detection of mercury(II) ions

2020

International audience; Reusable dual-channel optical sensors for Hg2+ ions were prepared by Langmuir-Schaefer (LS) method from amphiphilic (trans-A2)BC-type porphyrins functionalized at meso-positions of the tetrapyrrolic macrocycle by sterically demanding diethoxyphosphoryl and mesityl groups as well as electron donating RO, RS or RNH substituents (R = n-C8H17). These three novel amphiphilic porphyrin derivatives were synthesized in good yields and their floating films at the air⎯water interface were investigated. In these monolayers, porphyrin molecules display a slipped stack-of-card orientation, but their strong π stacking is prohibited by bulky diethoxyphosphoryl and mesityl groups. T…

Metal thin-film temperature sensor embedded in heat-sink for CPV cells characterization

2014

The efficiency of a photovoltaic cell is dependent on its temperature, for this reason an accurate measurement of this parameter is important to fully characterize the device and to optimize its performance. For CPV applications a significant heat flux is needed to remove excess heat from the cell towards a heat sink, making it difficult to derive the cell temperature. In fact, measurements performed directly between the cell and the heat-sink, by use of commercial bulk sensors, would produce a significant disturbance in the heat flow; on the other hand, a measurement performed out of the cell / heat sink axis would be subject to large uncertainties, due to the high radial temperature gradi…