Temperature-Dependent Carrier Extraction and the Effects of Excitons on Emission and Photovoltaic Performance in Cs0.05FA0.79MA0.16Pb(I0.83Br0.17)3 Solar Cells.

The photovoltaic parameters of triple cation perovskite [Cs0.05FA0.79MA0.16Pb(I0.83Br0.17)3] solar cells are investigated focusing on the electro-optical properties and differences in performance at low and high temperatures. The signature of a parasitic barrier to carrier extraction is observed at low temperatures, which results in a loss of performance at T < 200 K. Intensity-dependent measurements indicate extraction across this parasitic interface is limited by a combination of the exciton binding energy and thermionic emission. However, the photovoltaic performance of the device is recovered at low intensity─where the photocarrier generation rate threshold is lower than the thermionic extraction rate. Loss of solar cell performance is also observed to be strongly correlated to an increase in photoluminescence intensity, indicating inhibited carrier extraction results in strong radiative recombination and that these systems do not appear to be limited by significant thermally activated non-radiative processes. Evidence of limited carrier extraction due to excitonic effects is also observed with a strong anti-correlation in photoluminescence and carrier extraction observed at lower temperatures.

Factores asociados al estrés laboral en trabajadores de seis países de Latinoaméricaies / Factors associated with work-related stress in workers in six Latin American countries

Introducción: el estrés es uno de los problemas más frecuentes entre la población laboral, ocasiona repercusiones de la esfera mental que pueden tener consecuencias en el ambiente de trabajo. Objetivo: determinar los factores socio-laborales asociados al estrés entre los trabajadores de Latinoamérica. Metodología: se realizó una investigación observacional multicéntrica, se usó una escala validada para la medición del estrés (Alpha de Cronbach=0,73), se consideró estresados a los que estuvieron en el tercil superior de las respuestas totales. Se usó la estadística bivariada y multivariada para encontrar asociaciones versus otras variables sociales y laborales; a través de los modelos lineales generalizados. Resultados: respondieron la totalidad de preguntas 2608 rabajadores. El país con más nivel de estrés fue Venezuela (63%). En el análisis multivariado, estuvo asociado a una mayor frecuencia de estrés el sexo femenino (RPa: 1,21; IC95%: 1,10-1,33; valor p<0,001); usando como comparación al país de Venezuela, todos los otros países tuvieron una menor frecuencia de estrés: Perú (p<0,001), Colombia (p<0,001), Ecuador (p=0,016), Honduras (p<0,001) y Panamá (p=0,001), todas estas variables se ajustaron por la edad, los años de trabajo previo y el tipo de trabajador. Discusión: el estrés laboral se asoció al sexo y al país donde se realizó la encuesta; posiblemente esto se deba al contexto político que ocurre actualmente en Venezuela, lo que vuelve a poner en relevancia la importancia de la salud mental en los trabajadores, ya que, pueden generar problemas serios

Background: stress is one of the most frequent problems among the working population, causes repercussions of the mental sphere that can have consequences in work environment. Objective: To determine the socio-labor factors associated with stress among workers in Latin America. Methods: multicentric observational research was carried out, a validated scale for stress measurement (Cronbach's Alpha = 0.73) was used, it was considered stressed to those who were in the upper tertile of the total responses. Bivariate and multivariate statistics were used to find associations versus other social and labor variables; Through the generalized linear models. Results: all 2608 workers answered all questions. The country with the highest level of stress was Venezuela (63%). In the multivariate analysis, the female sex (PR: 1.21, 95% CI: 1.10-1.33, p value <0.001) was associated with a higher frequency of stress; (p <0.001), Colombia (p <0.001), Ecuador (p = 0.016), Honduras (p <0.001), and Panama (p <0.001). = 0.001), all of these variables were adjusted for age, previous years of work and type of worker. Discussion: labor stress was associated with sex and the country where the survey was conducted; This may be due to the political context that currently occurs in Venezuela, which again highlights the importance of mental health in workers, as they can generate serious problems