It is widely accepted that mobile ions are responsible for the slow electronic responses observed in metal halide perovskite-based optoelectronic devices, and strongly influence long-term operational stability. Electrical characterisation methods mostly observe complex indirect effects of ions on bulk/interface recombination, struggle to quantify the ion density and mobility, and are typically not able to fully quantify the influence of the ions upon the bulk and interfacial electric fields. We analyse the bias-assisted charge extraction (BACE) method for the case of a screened bulk electric field, and introduce a new characterisation method based on BACE, termed ion drift BACE.
View Article and Find Full Text PDFMultijunction photovoltaics (PVs) are gaining prominence owing to their superior capability of achieving power conversion efficiencies (PCEs) beyond the radiative limit of single-junction cells, where improving narrow bandgap tin-lead perovskites is critical for thin-film devices. With a focus on understanding the chemistry of tin-lead perovskite precursor solutions, we herein find that Sn(II) species dominate interactions with precursors and additives and uncover the exclusive role of carboxylic acid in regulating solution colloidal properties and film crystallisation, and ammonium in improving film optoelectronic properties. Materials that combine these two function groups, amino acid salts, considerably improve the semiconducting quality and homogeneity of perovskite films, surpassing the effect of the individual functional groups when introduced as part of separate molecules.
View Article and Find Full Text PDFSalmonella enterica serotype Typhimurium (Salmonella) resides and multiplies intracellularly in cholesterol-rich compartments called Salmonella-containing vacuoles (SCVs) with actin-rich tubular extensions known as Salmonella-induced filaments (SIFs). SCV maturation depends on host-derived cholesterol, but the transport mechanism of low-density lipoprotein (LDL)-derived cholesterol to SCVs remains unclear. Here we find that peroxisomes are recruited to SCVs and function as pro-bacterial organelle.
View Article and Find Full Text PDFFungal sexual reproduction is controlled by the mating-type () locus. In contrast to a majority of species in the phylum Basidiomycota that have tetrapolar mating-type systems, the opportunistic human pathogen employs a bipolar mating-type system, with two mating types ( and α) determined by a single locus that is unusually large (~120 kb) and contains more than 20 genes. While several genes are associated with mating and sexual development, others control conserved cellular processes (e.
View Article and Find Full Text PDFBackground: Previous research has suggested that the prevalence of risk factors for cardiometabolic diseases is higher in South Asians, with premature presentation common in this subpopulation.
Aim: To explore this further, we assessed the prevalence of metabolic syndrome (MetS) components and risk factors among young adults.
Methods: This was a cross-sectional, epidemiological, institution-based study conducted at the Medical College in Eastern India.