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Perovskite solar cells are actively investigated for their potential as highly efficient and cost-effective photovoltaic devices. However, a significant challenge in their practical application is enhancing their durability. Particularly, these cells are expected to be subjected to heating by sunlight in real-world operating environments. Therefore, high-temperature durability and device operation under such conditions are critical. Our study aims to improve the durability of perovskite solar cells for practical applications by examining their temperature coefficients at elevated temperatures using MA-free compositions. We assessed these coefficients and investigated their correlation with the ideality factor, revealing that carrier recombination markedly affects the temperature behavior of these cells. Our methodology involves simple J-V measurements to evaluate device degradation at high temperatures, paving the way for further research to enhance device performance in such environments., (© 2024 Wiley-VCH GmbH.)

Compositional engineering of organic-inorganic metal halide perovskite allows for improved optoelectrical properties, however, phase segregation occurs during crystal nucleation and limits perovskite solar cell device performance. Herein, we show that by applying tetrabutylammonium bistriflimide as an additive in the perovskite precursor solution, ultra-uniform perovskite crystals are obtained, which effectively increases device performance. As a result, power conversion efficiencies (PCEs) of 24.5% in a cell and 21.2% in a module are achieved, together with high stability under illumination, humidity and elevated thermal conditions., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Chemical bath deposition (CBD) is an effective technique used to produce high-quality SnO 2 electron transport layers (ETLs) employed in perovskite solar cells (PSCs). By optimizing the CBD process, high-quality SnO 2 films are obtained with minimal oxygen vacancies and close energy level alignment with the perovskite layer. In addition, the 3D perovskite layers are passivated with n-butylammonium iodide (BAI), iso-pentylammonium iodide (PNAI), or 2-methoxyethylammonium iodide (MOAI) to form 3D/2D heterojunctions, resulting in defect passivation, suppressing ion migration and improving charge carrier extraction. As a result of these heterojunctions, the power conversion efficiency (PCE) of the PSCs increased from 21.39% for the reference device to 23.70% for the device containing the MOAI-passivated film. The 2D perovskite layer also provides a hydrophobic barrier, thus enhancing stability to humidity. Notably, the PNAI-based device exhibited remarkable stability, retaining approximately 95% of its initial efficiency after undergoing 1000-h testing in an N 2 environment at room temperature., (© 2024 The Author(s). Small published by Wiley‐VCH GmbH.)

The power conversion efficiency of perovskite solar cells continues to increase. However, defects in perovskite materials are detrimental to their carrier dynamics and structural stability, ultimately limiting the photovoltaic characteristics and stability of perovskite solar cells. Herein, we report that 6H polytype perovskite effectively engineers defects at the interface with cubic polytype FAPbI 3 , which facilitates radiative recombination and improves the stability of the polycrystalline film. We particularly show the detrimental effects of shallow-level defect that originates from the formation of the most dominant iodide vacancy (V I + ) in FAPbI 3 . Furthermore, additional surface passivation on top of the hetero-polytypic perovskite film results in an ultra-long carrier lifetime exceeding 18 μs, affords power conversion efficiencies of 24.13% for perovskite solar cells, 21.92% (certified power conversion efficiency: 21.44%) for a module, and long-term stability. The hetero-polytypic perovskite configuration may be considered as close to the ideal polycrystalline structure in terms of charge carrier dynamics and stability., (© 2024. The Author(s).)

Perovskite solar cells (PSCs) are among the most promising photovoltaic technologies owing to their exceptional optoelectronic properties 1,2 . However, the lower efficiency, poor stability and reproducibility issues of large-area PSCs compared with laboratory-scale PSCs are notable drawbacks that hinder their commercialization 3 . Here we report a synergistic dopant-additive combination strategy using methylammonium chloride (MACl) as the dopant and a Lewis-basic ionic-liquid additive, 1,3-bis(cyanomethyl)imidazolium chloride ([Bcmim]Cl). This strategy effectively inhibits the degradation of the perovskite precursor solution (PPS), suppresses the aggregation of MACl and results in phase-homogeneous and stable perovskite films with high crystallinity and fewer defects. This approach enabled the fabrication of perovskite solar modules (PSMs) that achieved a certified efficiency of 23.30% and ultimately stabilized at 22.97% over a 27.22-cm 2 aperture area, marking the highest certified PSM performance. Furthermore, the PSMs showed long-term operational stability, maintaining 94.66% of the initial efficiency after 1,000 h under continuous one-sun illumination at room temperature. The interaction between [Bcmim]Cl and MACl was extensively studied to unravel the mechanism leading to an enhancement of device properties. Our approach holds substantial promise for bridging the benchtop-to-rooftop gap and advancing the production and commercialization of large-area perovskite photovoltaics., (© 2024. The Author(s).)

Recent advances in research suggest that aging has a controllable chronic inflammatory disease aspect. Aging systemic T cells, which secrete pro-inflammatory factors, affect surrounding somatic cells, and accelerate the aging process through chronic inflammation, have attracted attention as potential therapeutic targets in aging. On the other hand, there are few reports on the aging of the intestinal immune system, which differs from the systemic immune system in many ways. In the current study, we investigated the age-related changes in the intestinal immune system, particularly in T cells. The most significant changes were observed in the CD4 + T cells in the small intestinal IEL, with a marked increase in this fraction in old mice and reduced expression of CD27 and CD28, which are characteristic of aging systemic T cells. The proliferative capacity of aging IEL CD4 + T cells was significantly more reduced than that of aging systemic T cells. Transcriptome analysis showed that the expression of inflammatory cytokines was not upregulated, whereas Cd8α , NK receptors, and Granzymes were upregulated in aging IEL CD4 + T cells. Functional analysis showed that aging IEL T cells had a higher cytotoxic function against intestinal tumor organoids in vitro than young IEL T cells. scRNAseq revealed that splenic T cells show a transition from naïve to memory T cells, whereas intestinal T cells show the emergence of a CD8αα + CD4 + T cell fraction in aged mice, which is rarely seen in young cells. Further analysis of the aging IEL CD4 + T cells showed that two unique subsets are increased that are distinct from the systemic CD4 + T cells. Subset 1 has a pro-inflammatory component, with expression of IFNγ and upregulation of NFkB signaling pathways. Subset 2 does not express IFNγ , but upregulates inhibitory molecules and nIEL markers. Expression of granzymes and Cd8a was common to both. These fractions were in opposite positions in the clustering by UMAP and had different TCR repertoires. They may be involved in the suppression of intestinal aging and longevity through anti-tumor immunity, elimination of senescent cells and stressed cells in the aging environment. This finding could be a breakthrough in aging research., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Yonemoto, Nemoto, Morikawa, Shibayama, Oshima, Nagaishi, Mizutani, Ito, Fujii and Okamoto.)