Persistent photovoltage in methylammonium lead iodide perovskite solar cells

Open circuit voltage decay measurements are performed on methylammonium lead iodide (CH3NH3PbI3) perovskite solar cells to investigate the charge carrier recombination dynamics. The measurements are compared to the two reference polymer-fullerene bulk heterojunction solar cells based on P3HT:PC60BM and PTB7:PC70BM blends. In the perovskite devices, two very different time domains of the voltage decay are found, with a first drop on a short time scale that is similar to the organic solar cells. However, two major differences are also observed. 65-70% of the maximum photovoltage persists on much longer timescales, and the recombination dynamics are dependent on the illumination intensity.Comment: 5 pages, 3 figure

Derecho a una muerte digna

[ES]Mediante esta investigación comenzaremos concretaremos a lo que el término eutanasia hace referencia y su diferenciación con otros conceptos médicos. Continuaremos estableciendo las bases del debate que suscita la tan controvertida práctica de ayuda para morir, exponiendo de igual forma, los argumentos que se utilizan frente a su regulación. Para finalizar el estudio, analizaremos su panorama legal, centrándonos primero en la nueva ley de la eutanasia en España, aprobada en el pasado 2021 y concluyendo con el marco internacional legislativo, haciendo una diferenciación entre las distintas regulaciones, planteando ciertos supuestos prácticos de igual forma.[EU]Ikerketa honen bitartez eutanasia terminoak zeri egiten dion erreferentzia argituko dugu eta beste mediku kontzeptuetatik bereizten hasiko gara aldi berean. Laguntzen hiltzeko praktika gatazkatsuak eragiten duen eztabaidaren oinarriak ezartzen jarraituko dugu, era berean, haren erregulazioaren aurka erabiltzen diren argudioak azaleratuz. Azterlana amaitzeko, bere panorama juridikoa aztertuko dugu, lehenik eta behin Espainian 2021ean onartutako eutanasiaren lege berriari erreparatuz eta nazioarteko legegintza-esparruarekin amaituz, araudi ezberdinen arteko bereizketa eginez, era berean zenbait hipotesi praktiko planteatuz.[EN]Through this investigation we will begin to specify what the term euthanasia refers to and its differentiation from other medical concepts. We will continue to provide the basis for the debate raised by the highly controversial practice of aid in dying, exposing in the same way the arguments used against its regulation. To finish the study, we will analyze its legal panorama, focusing first on the new euthanasia law in Spain, approved in the past 2021 and concluding with the international legislative framework, making a differentiation between the different regulations, raising certain practical assumptions in the same wa

[Ir(C^N)2(N^N)]+ emitters containing a naphthalene unit within a linker between the two cyclometallating ligands

The synthesis of four cyclometallated [Ir(C^N) 2 (N^N)][PF 6 ] compounds in which N^N is a substituted 2,2’- -bipyridine (bpy) ligand and the naphthyl-centred ligand 2,7-bis(2-(2-(4-(pyridin-2-yl)phenoxy)ethoxy) ethoxy)naphthalene provides the two cyclometallating C^N units is reported. The iridium( III ) complexes have been characterized by 1 H and 13 C NMR spectroscopies, mass spectrometry and elemental analysis, and their electrochemical and photophysical properties are described. Comparisons are made with a model [Ir(ppy) 2 (N^N)][PF 6 ] compound (Hppy = 2-phenylpyridine). The complexes containing the naphthyl-unit exhibit similar absorption spectra and excitation at 280 nm leads to an orange emission. The incorporation of the naphthalene unit does not lead to a desirable blue contribution to the emission. Density functional theory calculations were performed to investigate the geometries of the complexes in their ground and first triplet excited states, as well as the energies and compositions of the highestoccupied and lowest unoccupied molecular orbital (HOMO and LUMO) manifolds. Trends in the HOMO– LUMO gaps agree with those observed electrochemically. The energy difference between the LUMO and the lowest unoccupied MO located on the naphthyl unit (LUMO+7) is large enough to explain why there is no contribution from the naphthyl-centred triplet excited state to the phosphorescence emission. Singlet excited states were also investigated. Light-emitting electrochemical cells (LECs) using the [Ir(C^N) 2 (N^N)][PF 6 ] and [Ir(ppy) 2 (N^N)][PF 6 ] complexes in the emissive layer were made and evaluated. The presence of the naphthyl-bridge between the cyclometallating units does not significantly alter the device response

Unconventional materials for light-emitting and photovoltaic applications

La motivación de este trabajo es el problema energético y éste ha sido abordado de dos maneras en esta tesis doctoral: promover un aumento de producción de energía mediante energías renovables junto con una reducción del consumo energético mediante el uso de sistemas más eficientes. Para este propósito, en esta tesis se han desarrollado dispositivos electroluminiscentes y fotovoltaicos novedosos de bajo coste y eficientes. En concreto, el trabajo se ha focalizado en el desarrollo de células electroquímicas emisoras de luz (LECs) emisoras en el rojo e infrarrojo cercano y en la mejora de su estabilidad. Así como en la fabricación de células solares de perovskita de alta eficiencia. Los dispositivos LECs han sido fabricados con complejos de metales de transición iónicos basados en el complejo [Ir(ppy)2(btzpy)][PF6], siendo (ppy = 2-fenilpiridinato y btzpy = 2-(piridin-2-yl)benzo[d]tiazol), manteniendo el ligando ppy constante y variando la funcionalización del ligando btzpy o el propio ligando btzpy. Los dispositivos preparados con la serie de complejos presentaron emisión electroluminiscente desde el rojo al infrarrojo cercano. A pesar de los moderados valores de luminancia máxima obtenidos, los dispositivos presentaron una extremada alta estabilidad con tiempos de vida medio entre 1000 y 6000 h, siendo los dispositivos LECs emisores en el rojo más estables publicados hasta la fecha. Los valores de EQEs obtenidos fueron moderados, pero considerables a pesar de los bajos valores de PLQY y las altas densidades de corriente pulsada empleadas. Además, se ha demostrado en este trabajo la modificación de los niveles de luminancia junto con una reducción del tiempo de encendido y sin pérdida de estabilidad cuando a los dispositivos fueron aplicados densidades de corriente muy altas. Para el desarrollo de células solares basadas en perovskita de alta eficiencia se realizaron dos acciones: estudio del efecto del espesor de la capa absorbente de luz en el rendimiento de la célula solar y la influencia de las capas transportadoras de carga en células solares tipo p-i-n y n-i-p. Estos trabajos pudieron ser llevados a cabo debido al preciso control del espesor de las capas mediante su deposición por la técnica de evaporación a vacío. En primer lugar se fabricaron una serie de capas de MAPbI3 a vacío con espesores entre 210 y 900 nm y posteriormente se implementaron en dispositivos tipo p-i-n. La fotocorriente generada se vio mejorada al aumentar el espesor del material absorbente de luz, pero la extracción de la carga se vio afectada, probablemente debido a la baja conductividad de la capa transportadora de huecos. La oxidación parcial de esta capa en una célula solar con capa absorbente de luz muy gruesa (900 nm) mejoró la extracción de las cargas viéndose el rendimiento de la célula solar recuperado, obteniendo valores similares al dispositivo más eficiente de la serie con capa absorbente de luz más fina. En este trabajo se demostró que con capas orgánicas no limitantes, el rendimiento fotovoltaico de células solares basadas en perovskita depositadas a vacío es independiente del espesor de la capa absorbente MAPbI3. Este trabajo también demostró que la longitud de difusión de carga en células solares cuya capa MAPbI3 ha sido evaporada a vacío es larga. Para mejorar la extracción de la carga en los dispositivos, se fabricaron células solares basadas en perovskita tipo p-i-n y n-i-p, cuya capa absorbente de luz (MAPbI3) fue depositada entre capas intrínsecas y dopadas. En este estudio, se realizó una optimización de la concentración de dopante en las capas dopadas y se investigó la función e influencia de las capas intrínsecas y dopadas en el rendimiento de las células solares para la obtención de muy alta eficiencia. Se observó que la presencia de ambas capas es necesaria para tan altas eficiencias. Una vez optimizado el dispositivo, las células solares presentaron eficiencias de 16.5% (p-i-n) y 20% (n-i-p) sin histéresis. Estos valores son los más altos publicados en células solares basadas en perovskita depositada por evaporación en vacío y cuyo material absorbente de luz es MAPbI3.The motivation of this thesis is to reduce the energy consumption to generate illumination and the amount of fuel fossil employed in the generation of energy. For this purpose, novel, efficient and low-cost electroluminescent and photovoltaic devices need to be developed. The work was focused on the development of red- and near-infrared LECs and the improvement of the device stability. The iTMCs studied were based on the [Ir(ppy)2(btzpy)][PF6] complex (ppy = 2-phenylpyridinate and btzpy = 2-(pyridin-2-yl)benzo[d]thiazole) and all of the complexes showed red- and near-infrared photoluminescence in the solid-state with moderate PLQYs values (<18%). The LECs prepared with the complexes also exhibit red to near-infrared electroluminescence. Although the maximum luminance values were moderate, they exhibited extremely high device stability with lifetimes in the range of 1000–6000 h, being the most stable red-emitting LECs reported up to date. The EQEs obtained were moderate (EQE<2%), however, these values were impressive in view of its low PLQY values and the high current density applied. Moreover, the possibility of tuning the luminance levels was demonstrated, having a fast response with almost no loss in device stability, maintaining its impressive characteristics by increasing the average current density. An in-depth study of the photovoltaic efficiency by increasing the photocurrent obtained through modification of the perovskite thickness was performed. A series of vacuum-deposited MAPbI3 layers with layer thicknesses ranging from 210 to 900 nm were fabricated and implemented into p-i-n devices. The JSC was enhanced when the perovskite thickness was increased but the FF and hence the PCE was reduced due to the low mobility of the polyTPD layer. The partial oxidation of the polyTPD layer increases its conductivity and the device recovers the FF reaching a PCE of 12.7%, being the same high efficiency than the most efficient device of the series with thinner perovskite films (12%). In this work was demonstrated that with non-limiting organic layers, the PV performance of vacuum-deposited perovskite solar cells is independent on the perovskite layer thickness and that the charge carrier diffusion length is not limiting in the devices. Fully vacuum-deposited p-i-n and n-i-p perovskite solar cells, employing a MAPbI3 perovskite layer deposited between an intrinsic and doped n- or p- type organic charge transport layers, respectively, were fabricated. The optimization of the dopant concentration was carried out and it was found that the presence of the undoped and doped charge transport layers were required for highly efficient solar cells. The optimized solar cells lead to hysteresis-free and very high efficiencies exceeding 16.5% (p-i-n) and 20% (n-i-p), the highest efficiencies reported for vacuum-deposited perovskite and for MAPbI3-based solar cells

Estudio de utilización de nirmatrelvir/ritonavir en tres centros de atención primaria durante 2022

Introduction: Nirmatrelvir/ritonavir (Paxlovid®) is the only oral treatment authorized in Europe to treat COVID-19 disease in adults who do not require supplemental oxygen and who are at high risk for progression to severe COVID-19. It is available in Spain after validation due to the profile of interactions and warnings for use. The objective is to determine effectiveness, safety and management of interactions. Method: Retrospective study of all patients on validated nirmatrelvir/ritonavir treatment at three urban health centres during 2022. Effectiveness was the proportion of participants without COVID-19-related hospitalization or death from any cause through day 28. Results: 24 patients were analyzed. It was considered effective in 23 (95.8 %). More than 80 % of patients presented potential interaction with the concomitant medication, recommending the temporary suspension of medications, highlighting simvastatin and metamizole. Conclusions: Nirmatrelvir/ritonavir has been considered effective but difficult to manage in polymedicated polypathological patients.Introducción: Nirmatrelvir/ritonavir (Paxlovid®) es el único tratamiento oral autorizado en Europa para tratar la enfermedad por COVID-19 en adultos que no requieren aporte de oxígeno suplementario y que tienen un riesgo alto de progresar a COVID-19 grave. Está disponible en España previa validación debido al perfil de interacciones y advertencias de uso. El objetivo es determinar efectividad, seguridad y manejo de interacciones. Método: Estudio retrospectivo de todos los pacientes con tratamiento validado de nirmatrelvir/ritonavir en tres centros de salud urbanos durante 2022. La efectividad fue la proporción de participantes sin hospitalización relacionada con COVID-19 o muerte por cualquier causa hasta el día 28.  Resultados: Se analizaron 24 pacientes. Se consideró efectivo en 23 (95,8 %). Más del 80 % de pacientes presentaban interacción potencial con la medicación concomitante, recomendándose la suspensión temporal de medicamentos destacando simvastatina y metamizol. Conclusiones: Nirmatrelvir/ritonavir se ha considerado efectivo pero con difícil manejo en pacientes pluripatológicos polimedicados.

Análisis de los flujos de humedad y estructura térmica de los eventos de nieve en la transición Atlántico - Mediterránea del Valle del Ebro

Ponencia presentada en: XXXIV Jornadas Científicas de la AME y el XVII Encuentro Hispano Luso de Meteorología celebrado en Teruel, del 29 de febrero al 2 de marzo de 2016

Problemas relacionados con la medicación que causan ingresos hospitalarios

ResumenObjetivoLos problemas relacionados con los medicamentos (PRM) están vinculados al tratamiento farmacológico del paciente e interfieren o pueden interferir con los resultados esperados en su salud. El presente estudio tiene como objetivo determinar la prevalencia de los PRM en los pacientes de un centro de salud urbano que son causa de ingreso en su hospital de referencia, y su evitabilidad.DiseñoEs un estudio observacional de tipo descriptivo y retrospectivo.EmplazamientoCENTRO de Salud Les Corts, que es un centro de salud urbano y docente con una población asignada de 32.318 habitantes.ParticipantesUsuarios del CS Les Corts ingresados en el Hospital Clínico de Barcelona desde agosto de 2005 a enero de 2006.Resultados y mediciones principalesUna pareja de un farmacéutico y un médico de familia analizan las historias clínicas y determinan la presencia o no de PRM. El 13,4% de todas las altas presentan PRM, que en su mayoría están implicados en el ingreso hospitalario (12%). Un 57,3% del total de altas con un PRM como causa del ingreso hospitalario se ha considerado evitable. Los ingresos por PRM se concentran en los servicios de medicina interna, cardiología y neumología. Los problemas de salud motivo de ingreso hospitalario por PRM son mayoritariamente circulatorios (38,5%) y respiratorios (11,5%).ConclusionesEl número de ingresos debidos a problemas relacionados con la medicación es elevado y evitable.AbstractObjectiveDrug related problems (DRP) are health problems associated with the pharmacological treatment of patients and interfere or can interfere with the expected results on their health. The aim of this study is to determine the prevalence of DRP in patients from an urban health centre that lead to hospitalisation, and its prevention.DesignIt is a retrospective, observational and descriptive study.SettingLes Corts Health Centre (HC), which is an urban health and teaching centre with a reference population of 32,318 inhabitants.ParticipantsUsers of the les Corts HC admitted to the Barcelona Hospital Clinic from August 2005 to January 2006.Results and main outcome measurementsA pharmacist and a family doctor analysed the clinical histories and determined whether or not there was a DRP. A DRP was present in 13.4% of all hospital discharges, and 12% were implicated in the hospital admission. It was considered that 57.3% of all the discharges with a DRP as the causing factor in the hospital admission were avoidable. Admissions due to DRP were mainly in internal medicine, cardiology and pneumology. The health problems that lead to hospital admission due to DRP are mainly circulatory (38.5%) and respiratory (11.5%).ConclusionsThe number of hospital admissions due to drug related problems is avoidably high

Vacuum Deposited Triple-Cation Mixed-Halide Perovskite Solar Cells

Hybrid lead halide perovskites are promising materials for future photovoltaics applications. Their spectral response can be readily tuned by controlling the halide composition, while their stability is strongly dependent on the film morphology and on the type of organic cation used. Mixed cation and mixed halide systems have led to the most efficient and stable perovskite solar cells reported, so far they are prepared exclusively by solution-processing. This might be due to the technical difficulties associated with the vacuum deposition from multiple thermal sources, requiring a high level of control over the deposition rate of each precursor during the film formation. In this report, thermal vacuum deposition with multiple sources (3 and 4) is used to prepare for the first time, multications/anions perovskite compounds. These thin-film absorbers are implemented into fully vacuum deposited solar cells using doped organic semiconductors. A maximum power conversion efficiency of 16% is obtained, with promising device stability. The importance of the control over the film morphology is highlighted, which differs substantially when these compounds are vacuum processed. Avenues to improve the morphology and hence the performance of fully vacuum processed multications/anions perovskite solar cells are proposed

High efficiency single-junction semitransparent perovskite solar cells

Semitransparent perovskite solar cells with a high power conversion efficiency (PCE) above 6% and 30% full device transparency have been achieved by implementing a thin perovskite layer and a simple foil compatible layout

Modulating the electron transporting properties of Subphthalocyanines for inverted perovskite solar cells

The lack of organic non-fullerene ETMs with good electron transport and device stability is an important problem for the further development and commercialization of perovskite solar cells. Herein, the use of SubPcs as ETMs in PSCs is explored. To this end, we analyze the influence of SubPc peripheral functionalization on the efficiency and stability of p-i-n PSCs. Specifically, ETMs based on three SubPcs (with either six or twelve peripheral fluorine and chlorine atoms) have been incorporated into PSCs with the perovskite layer deposited by solution processing (CsFAMAPbIBr). The device performance and morphology of these devices are deeply analyzed using several techniques, and the interfacial effects induced by the SubPcs are studied using photoluminescence and TR-PL. It is observed that the device stability is significantly improved upon insertion the SubPc layer. Moreover, the impact of the SubPc layer-thickness is assessed. Thus, a maximum power conversion efficiency of 13.6% was achieved with the champion devic