Design and Characterization of Hybrid Perovskite for New Generation Solar Cells

Le perovskiti sono semiconduttori con caratteristiche optoelettroniche ideali per l’applicazione fotovoltaica (elevato assorbimento, alta mobilità di carica) e con un basso costo. Tuttavia, la loro applicazione commerciale è limitata dall’instabilità di questo materiale. Il degrado della perovskite è causato da alcuni fattori esterni come ossigeno e umidità. In questa tesi sono state studiate entrambe le strutture (NIP e PIN) delle celle solari a perovskite. Per renderle più stabili ed efficienti sono state trattate con nuovi metodi di passivazione e con materiali di recente sintesi che hanno portato al raggiungimento dell’obiettivo. Sono state anche usate diverse tecniche di caratterizzazione per comprendere le ragioni dei miglioramenti nelle prestazioni di questi dispostivi. Questo ha permesso di ottenere una maggiore conoscenza dei meccanismi dei miglioramenti e di conseguenza a una più vicina commercializzazione di questo materiale.Perovskites are semiconductors with ideal optoelectronic properties (like high absorption and high charge mobility) for photovoltaic applications and at a low cost. However, their commercial application is limited by the instability of this material. The degradation of perovskite is caused by some external factors such as oxygen and humidity. In this thesis both structures (NIP and PIN) of perovskite solar cells have been studied. To make them more stable and efficient, they have been treated with new passivation methods and with recently synthesized materials that have led to the achievement of the goal. Various characterization techniques were also used to understand the reasons for the performance improvements of these devices. This allowed obtaining a greater knowledge of the mechanisms of the improvements and consequently to closer commercialization of these perovskites

ECMO for COVID-19 patients in Europe and Israel

Since March 15th, 2020, 177 centres from Europe and Israel have joined the study, routinely reporting on the ECMO support they provide to COVID-19 patients. The mean annual number of cases treated with ECMO in the participating centres before the pandemic (2019) was 55. The number of COVID-19 patients has increased rapidly each week reaching 1531 treated patients as of September 14th. The greatest number of cases has been reported from France (n = 385), UK (n = 193), Germany (n = 176), Spain (n = 166), and Italy (n = 136) .The mean age of treated patients was 52.6 years (range 16–80), 79% were male. The ECMO configuration used was VV in 91% of cases, VA in 5% and other in 4%. The mean PaO2 before ECMO implantation was 65 mmHg. The mean duration of ECMO support thus far has been 18 days and the mean ICU length of stay of these patients was 33 days. As of the 14th September, overall 841 patients have been weaned from ECMO support, 601 died during ECMO support, 71 died after withdrawal of ECMO, 79 are still receiving ECMO support and for 10 patients status n.a. . Our preliminary data suggest that patients placed on ECMO with severe refractory respiratory or cardiac failure secondary to COVID-19 have a reasonable (55%) chance of survival. Further extensive data analysis is expected to provide invaluable information on the demographics, severity of illness, indications and different ECMO management strategies in these patients

Phase Change Perovskite Metasurfaces

We report the first dielectric perovskite metasurfaces with continuously tunable optical response across the visible spectrum via a small temperature gradient around room temperature, bearing potential applications in active light-emitting devices and spatial-light-modulators.</p

Molecular Biology Can Change the Classic Laboratory Approach for Intestinal Protozoan Infections

For many years microscopy has been considered the mainstay of the diagnosis of parasitic infections. In our laboratory, before the advent of molecular biology, the approach for the identification of parasitic infections in stools was the microscopic exam of three samples. Once we adopted molecular biology, a real-time PCR on one single sample was added to the classical coproparasitological exam of three samples. Given the high sensitivity of real-time PCR (Rt-PCR), we then decided to evaluate if a change of our routine was justified. In detail, we intended to assess if a much more practical routine, based on the analysis of a single fecal sample, was sufficiently sensitive to replace the routine described above. The new approach to be evaluated included, on the same and unique fecal sample, a classical coproparasitological exam plus Rt-PCR. The data obtained showed that the sensitivity of the new proposed approach remains very high, despite the reduction of coproparasitological exams from three to one, with the advantage of reducing costs and saving time, both for patients and for the laboratory

Imaging and quantifying non-radiative losses at 23% efficient inverted perovskite solar cells interfaces

International audienceInterface engineering through passivating agents, in the form of organic molecules, is a powerful strategy to enhance the performance of perovskite solar cells. Despite its pivotal function in the development of a rational device optimization, the actual role played by the incorporation of interfacial modifications and the interface physics therein remains poorly understood. Here, we investigate the interface and device physics, quantifying charge recombination and charge losses in state-of-the-art inverted solar cells with power conversion efficiency beyond 23%-among the highest reported so far-by using multidimensional photoluminescence imaging. By doing that we extract physical parameters such as quasi-Fermi level splitting (QFLS) and Urbach energy enabling us to assess that the main passivation mechanism affects the perovskite/PCBM ([6,6]-phenyl-C 61-butyric acid methyl ester) interface rather than surface defects. In this work, by linking optical, electrical measurements and modelling we highlight the benefits of organic passivation, made in this case by phenylethylammonium (PEAI) based cations, in maximising all the photovoltaic figures of merit

Schistosomiasis screening of travelers from italy with possible exposure in Corsica, France

No abstract available; Lette