Search results for "OPEN-CIRCUIT VOLTAGE"
showing 10 items of 63 documents
Effect of NaClO disinfection/cleaning on passive films on AISI 316L
2020
Abstract 316 L stainless steel samples were passivated in NaClO containing solutions in order to simulate disinfection processes. Passive films were grown at the open circuit potential by immersion in NaClO aqueous solutions at different concentrations and temperature in order to understand how exposure to aggressive environments could affect subsequent corrosion resistance of SSs. In the attempt to study the passive film growth mechanism, in-situ Open Circuit Potential measurements were performed in the same growth solutions. Photoelectrochemical and impedance investigation of passive films was carried out in order to link their solid state properties with their corrosion behaviour.
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…
Transient drift‐diffusion simulation of the open circuit voltage decay in ionic perovskite solar cells
2021
Thermogalvanic corrosion of Alloy 31 in different heavy brine LiBr solutions
2012
Thermogalvanic corrosion generated between two electrodes of Alloy 31, a highly-alloyed austenitic stainless steel (UNS N08031), has been investigated imposing different temperature gradients in three deaerated LiBr solutions, under open circuit conditions by using a zero-resistance ammeter (ZRA). Besides EIS spectra were acquired in order to explain the obtained results. On the whole, cold Alloy 31 electrodes were anodic to hot Alloy 31 electrodes, since an increase in temperature favoured the cathodic behaviour of the hot electrode. Thermogalvanic corrosion of Alloy 31 in the LiBr solutions studied was not severe, although it negatively affects the corrosion resistance of the cold anode. …
Series resistance determination and further characterization of c-Si PV modules
2012
Abstract This paper presents a new algorithm for determination of the series resistance of crystalline-Si PV modules from individual illuminated I–V curves. The ideality factor and the reverse saturation current are then extracted in the classic way. The approach is applied to in-situ measured data from modules based on two types of mc-Si feedstock. The results indicate that the method yields physically meaningful parameters. An improved definition of local ideality factor is suggested, resulting in m-V plots unaffected by the series resistance. In addition, m-I plots are introduced for the first time. The novel differential techniques reveal an unexpected rise of the ideality factor at ope…
High voltage vacuum-deposited CH3NH3PbI3-CH3NH3PbI3 tandem solar cells
2018
The recent success of perovskite solar cells is based on two solid pillars: the rapid progress of their power conversion efficiency and their flexibility in terms of optoelectrical properties and processing methods. That versatility makes these devices ideal candidates for multi-junction photovoltaics. We report an optically optimized double junction CH3NH3PbI3–CH3NH3PbI3 tandem solar cell where the matched short-circuit current is maximized while parasitic absorption is minimized. The use of an additive vacuum-deposition protocol allows us to reproduce calculated stack designs, which comprise several charge selective materials that ensure appropriate band alignment and charge recombination…
Corrosion resistance of passive films on different stainless steel grades in food and beverage industry
2020
Abstract Passive films were grown on 304 L, 316 L and Duplex stainless steels by immersion at open circuit potential in solutions mimicking food and beverage industry environments. In acidic food stainless steel surfaces are covered by Cr rich passive films, and generalized dissolution occurs on their surface with consequent ions release into the electrolyte. In fatty food the concentration of released ions is significantly lower since generalized corrosion does not occur, but the loss on MnS inclusions strongly reduces the polarization resistance in this environment especially for 304 L due to its higher localized corrosion susceptibility with respect to the other grades.
Fullerene imposed high open-circuit voltage in efficient perovskite based solar cells
2016
Five different commercially available fullerenes are evaluated as hole blocking/electron transporting materials in p–i–n methylammonium lead iodide perovskite solar cells using a vacuum deposited perovskite absorber layer. A significant enhancement of the solar cell performance can be obtained by selecting a suitable fullerene derivative. Open-circuit voltages as high as 1.11 volts are obtained leading to a power conversion efficiency of 14.6%.
Meniscus coated high open-circuit voltage bi-layer solar cells
2012
Neat bi-layer solar cells of a fullerene acceptor and a cyanine dye donor were prepared using meniscus coating. Meniscus coating is very material efficient and leads to high quality pinhole-free films. The cells exhibit high open circuit voltages of 1 volt, only 0.8 eV below the band gap of the cyanine dye. This is one of the smallest differences reported for organic solar cells and illustrates an almost optimal donor-acceptor energy level alignment.
Influence of the intermediate density-of-states occupancy on open-circuit voltage of bulk heterojunction solar cells with different fullerene accepto…
2010
Electron density of states (DOS) and recombination kinetics of bulk heterojunction solar cells consisting of a poly(3-hexylthiophene) (P3HT) donor and two fullerene acceptors, either [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) or 4,4′-dihexyloxydiphenylmethano[60]fullerene (DPM6), have been determined by means of impedance spectroscopy. The observed difference of 125 mV in the output open-circuit voltage is attributed to significant differences of the occupancy of the DOS in both fullerenes. Whereas DPM6 exhibits a full occupation of the electronic band, occupancy is restricted to the tail of the DOS in the case of PCBM-based devices, implying a higher rise of the Fermi level in the D…