In our day-to-day lives, advances in lightweight and flexible photovoltaics will promote a new generation of soft electronics and machines requiring high power-per-weight. Ultrathin flexible perovskite solar cells (F-PSCs) with high power-per-weight have displayed a unique potential for specific applications where lower weight, higher flexibility, and conformability are indispensable. This Review highlights the recent progress and practical applications of ultrathin and lightweight F-PSCs and demonstrates the routes toward enhanced device efficiency and improved mechanical and environmental stability concerning the choice of flexible substrates and the development of high-performance functional layers and flexible transparent electrodes. The fabrication technologies for mass production of efficient F-PSCs at large scale are then summarized, including continuous roll-to-roll methods integrated with low-temperature process. Furthermore, the practical applications focused on self-powered wearable electronic devices, solar-powered miniature unmanned aerial vehicles, and even solar modules operating in near-space are elaborated. Finally, the current challenging issues and future perspective are discussed, aiming to promote more extensive applications and commercialization processes for lightweight F-PSCs.

During the past few years, Sn-based perovskites have been extensively investigated in the field of photovoltaics and are considered as one of the most promising alternatives for their Pb counterparts. For perovskite solar cells (PSCs), the rational design of the device architecture plays a critical role in obtaining high-performing devices, and architecture engineering has made a significant contribution to the development of Sn-based PSCs. In this Review, we summarize the advanced development of Sn-based PSCs from the viewpoint of architecture engineering. We begin with a demonstration of the distinctive characteristics of Sn-based perovskites, aiming at providing important guidance for architecture design toward high-performing PSCs. Next, up-to-date studies on the architecture engineering of Sn-based PSCs are comprehensively reviewed. Finally, the current challenges and future perspectives regarding architecture engineering of Sn-based PSCs are discussed, which we hope will guide further development toward efficient and stable Sn-based PSCs.

Epidemiological studies have associated high levels of airborne particulate matter (PM) with increased respiratory diseases. In order to investigate the mechanisms of air pollution-induced lung toxicity in humans, human bronchial epithelial cells (16HBE) were exposed to various concentrations of particles smaller than 2.5 μm (PM2.5) collected from Beijing, China. After observing that PM2.5 decreased cell viability in a dose-dependent manner, we first used Illumina RNA-seq to identify genes and pathways that may contribute to PM2.5-induced toxicity to 16HBE cells. A total of 539 genes, 283 up-regulated and 256 down-regulated, were identified to be significantly differentially expressed after exposure to 25 μg/cm2 PM2.5. PM2.5 induced a large number of genes involved in responses to xenobtiotic stimuli, metabolic response, and inflammatory and immune response pathways such as MAPK signaling and cytokine-cytokine receptor interaction, which might contribute to PM2.5-related pulmonary diseases. We then confirmed our RNA-seq results by qPCR and by analysis of IL-6, CYP1A1, and IL-8 protein expression. Finally, ELISA assay demonstrated a significant association between exposure to PM2.5 and secretion of IL-6. This research provides a new insight into the mechanisms underlying PM2.5-induced respiratory diseases in Beijing.

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The poor stability, in particular with respect to temperature, moisture, and light exposure, remains a ubiquitous impediment virtually for metal halide perovskite materials and devices in their future practical application. Herein, from the perspective of precursor solution chemistry, ionic liquid solvent methylammonium acetate (MAAc) is introduced to prepare high‐quality MAPbBr3 perovskite thin films in a one‐step air‐processing process without anti‐solvent treatment. Due to formation of pinhole‐free, uniform, and compact MAPbBr3 perovskite film, excellent amplified spontaneous emission (ASE) with high emission efficiency and low threshold is obtained under nanosecond laser. Furthermore, the prepared MAPbBr3 perovskite exhibits excellent two‐photon induced ASE with a low threshold of 100 µJ cm−2 under 800 nm femtosecond laser excitation. More importantly, in comparison with the traditional MAPbBr3 films prepared with N,N‐dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), the MAPbBr3 film prepared with MAAc shows excellent optical stability: no signs of degradation under more than 2 h pulsed laser excitation, stable ASE emission spectra under the humidity of 95% and ASE spectra can be stimulated when films are kept in air for more than 6000 h without encapsulation.