Mapping 123 million neonatal, infant and child deaths between 2000 and 2017

Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2—to end preventable child deaths by 2030—we need consistently estimated data at the subnational level regarding child mortality rates and trends. Here we quantified, for the period 2000–2017, the subnational variation in mortality rates and number of deaths of neonates, infants and children under 5 years of age within 99 low- and middle-income countries using a geostatistical survival model. We estimated that 32% of children under 5 in these countries lived in districts that had attained rates of 25 or fewer child deaths per 1,000 live births by 2017, and that 58% of child deaths between 2000 and 2017 in these countries could have been averted in the absence of geographical inequality. This study enables the identification of high-mortality clusters, patterns of progress and geographical inequalities to inform appropriate investments and implementations that will help to improve the health of all populations

Spray-Coated Lead-Free Cs<inf>2</inf>AgBiBr<inf>6</inf> Double Perovskite Solar Cells with High Open-Circuit Voltage

Lead-free Cs2AgBiBr6 double perovskite is considered a promising alternative photovoltaic absorber to the widely-used lead halide perovskite thanks to its easy processability, high stability and reduced toxicity. Herein, we report for the first-time spray processing for the deposition of Cs2AgBiBr6 double perovskite thin films. We compare microstructural (X-ray diffraction, scanning electron microscopy) and optoelectronic (absorbance, photoluminescence, photocurrent density versus applied voltage curves, electrochemical impedance spectroscopy) properties of spray-coated film with the spin-coated benchmark. Incorporation of the spray-coated Cs2AgBiBr6 double perovskite thin films in solar cells leads to a 2.3% photoconversion efficiency with high open-circuit voltage of 1.09 V. This study highlights the suitability of ultrasonic spray deposition for the optimization of Cs2AgBiBr6 solar cells in terms of light absorption properties and charge transfer at the Cs2AgBiBr6/hole transporting layer interface