Search results for "FOT"
showing 10 items of 1161 documents
Preparation and Characterization of Mixed Halide MAPbI3−xClx Perovskite Thin Films by Three‐Source Vacuum Deposition
2020
Chloride has been extensively used in the preparation of metal halide perovskites such as methylammonium lead iodide (MAPbI3-xClx), but its persistence and role in solution-processed materials has not yet been rationalized. Multiple-source vacuum deposition of perovskites enables a fine control over the thin-film stoichiometry, and allows to incorporate chemical species irrespectively of their solubility. In this communication, we present the first example of mixed MAPbI3-xClx thin films prepared by three-source vacuum deposition using MAI, PbI2 and PbCl2 as precursors. The optoelectronic properties of the material are evaluated through photovoltaic and electro-/photo-luminescent characteri…
Efficient Semitransparent Perovskite Solar Cells Based on Thin Compact Vacuum Deposited CH3NH3PbI3 Films
2022
Lead halide perovskite materials are promising candidates for the application of semitransparent solar cells due to their bandgap tunability and high device efficiencies. The high absorption coefficient of these materials, however, makes it difficult to attain high average visible transmittance values without compromising the power conversion efficiencies (PCEs). In this work, a co-evaporation process is employed to fabricate thin (50 and 100 nm) methylammonium lead iodide (MAPI) perovskite films and integrate them in semitransparent perovskite solar cells (ST-PSCs). Due to the compact nature of the thin MAPI films, the resultant fully vacuum and room temperature-processed devices demonstra…
Combinatorial Vacuum-Deposition of Wide Bandgap Perovskite Films and Solar Cells
2022
The development of vacuum-deposited perovskite materials and devices is partially slowed down by the minor research effort in this direction, due to the high cost of the required research tools. But there is also another factor, thermal co-deposition in high vacuum involves the simultaneous sublimation of several precursors with an overall deposition rate in the range of few Å s−1 . This leads to a deposition time of hours with only a single set of process parameters per batch, hence to a long timeframe to optimize even a single perovskite composition. Here we report the combinatorial vacuum deposition of wide bandgap perovskites using 4 sources and a non-rotating sample holder. By using sm…
ITO top-electrodes via industrial-scale PLD for efficient buffer-layer-free semitransparent perovskite solar cells
2022
The deposition of transparent conductive oxides (TCO) usually employs harsh conditions that are frequently harmful to soft/organic underlayers. Herein, successful use of an industrial pulsed laser deposition (PLD) tool to directly deposit indium tin oxide (ITO) films on semitransparent vacuum-deposited perovskite solar cells without damage to the device stack is demonstrated. The morphological, electronic, and optical properties of the PLD deposited ITO films are optimized. A direct relation between the PLD chamber pressure and the solar cell performance is obtained. The semitransparent perovskite solar cells prepared exclusively by vacuum-assisted techniques had fill factors of 78% and exc…
Long-term organic farming on a citrus plantation results in soil organic carbon recovery
2019
[ES] Se ha demostrado que el manejo del suelo bajo agricultura ecológica puede aumentar el contenido de carbono orgánico en el suelo moderando el incremento de los gases de efecto invernadero, pero hasta la fecha las evaluaciones cuantitativas basadas en mediciones a largo plazo han sido escasas, especialmente bajo condiciones mediterráneas. En esta investigación se examinaron los cambios en el contenido de carbono orgánico como respuesta a la agricultura ecológica con cobertura vegetal en una plantación de cítricos en el área mediterránea, utilizando una base de datos de 21 años. El incremento de contenido de carbono orgánico en el suelo fue más evidente tras cinco años desde el cambio del…
Rainfall simulation and Structure-from-Motion photogrammetry for the analysis of soil water erosion in Mediterranean vineyards
2016
[EN] Soil water erosion is a serious problem, especially in agricultural lands.Among these, vineyards deserve attention, because they constitute for the Mediterranean areas a type of land use affected by high soil losses. A significant problem related to the study of soil water erosion in these areas consists in the lack of a standardized procedure of collecting data and reporting results, mainly due to a variability among the measurement methods applied. Given this issue and the seriousness of soil water erosion in Mediterranean vineyards, this works aims to quantify the soil losses caused by simulated rainstorms, and compare them with each other depending on two different methodologies: (…
Effects of parent material on soil erosion within Mediterranean new vineyard plantations
2018
[EN] Parent material can determine specific physical and chemical soil properties and, therefore, soil erosion rates. However, for new vine plantations, there is not enough research on soil erosion assessment on different parent materials which could be helpful for agricultural management plans. The main aim of this research was to quantify soil erosion rates of two recent vineyard plantations under similar climate and land use management conditions, but on different parent materials, namely colluvium (2 years old) and marls (8 years old), located within the Les Alcusses valley vineyards in Eastern Spain. To achieve this goal, the ISUM (improved stock unearthing method) was applied. ISUM in…
Retrieval and assessment of CO2 uptake by mediterranean ecosystems using remote sensing and meteorological data
2014
Reseña de tesis doctoral
Lo spettacolo del naufragio Migrazioni, luoghi visuali e politica delle emozioni
2018
«No "we" should be taken for granted when the subject is looking at other people's pain». Referring to Three Guineas by Virginia Woolf, Susan Sontag argues for re-thinking the debate on images of war starting from a new and troubling point: the "we" at whom such shock-pictures are aimed. If the spectacle of suffering can turn into a silent and unproductive sympathy, it is only questioning its viewers and their geometries of power that the field of visibility can become a space of responsibility and cultural criticism. The aim of this paper is to move beyond the contemporary European representation of migrations and to critically explore the political, economic and cultural relations underly…
Characterization of cryopreserved rat liver parenchymal cells by metabolism of diagnostic substrates and activities of related enzymes
1992
The metabolism of testosterone and benzo(a)pyrene (BaP) which is mediated by diverse enzymes was determined in cryopreserved rat liver parenchymal cells and compared with that found in freshly isolated cells. In addition, the activities of single xenobiotic-metabolizing enzymes were measured by using specific substrates. The cytochrome P450 (P450)-mediated total metabolic conversion of testosterone was reduced to 55% in cryopreserved cells. The metabolite profile, i.e. the formation of single metabolites compared with total metabolic conversion, was however unchanged when compared with freshly isolated cells. A concomitant reduction in the activities of the involved P450 isoenzymes can ther…