Tin‐based perovskites with excellent optoelectronic properties and suitable band gaps are promising candidates for the preparation of efficient lead‐free perovskite solar cells (PSCs). However, it is challenging to prepare highly stable and efficient tin‐based PSCs because Sn2+ in perovskites can be easily oxidized to Sn4+ upon air exposure. Here we report the fabrication of air‐stable FASnI3 solar cells by introducing hydroxybenzene sulfonic acid or its salt as an antioxidant additive into the perovskite precursor solution along with excess SnCl2. The interaction between the sulfonate group and the Sn2+ ion enables the in situ encapsulation of the perovskite grains with a SnCl2–additive complex layer, which results in greatly enhanced oxidation stability of the perovskite film. The corresponding PSCs are able to maintain 80 % of the efficiency over 500 h upon air exposure without encapsulation, which is over ten times longer than the best result reported previously. Our results suggest a possible strategy for the future design of efficient and stable tin‐based PSCs.

2D van der Waals crystals, possessing excellent electronic and physical properties, have been intriguing building blocks for organic optoelectronic devices. Most of the 2D materials are served as hole transport layers in organic devices. Here,it is reported that solution exfoliated few layers black phosphorus (BP) can be served as an effective electron transport layer (ETL) in organic photovoltaics (OPVs) for the first time. The power conversion efficiencies (PCEs) of the BP‐incorporated OPVs can be improved to 8.18% in average with the relative enhancement of 11%. The incorporation of BP flakes with the optimum thickness of ≈10 nm can form cascaded band structure in OPVs, which can facilitate electron transport and enhance the PCEs of the devices. This study opens an avenue in using solution exfoliated BP as a highly efficient ETL for organic optoelectronics.

The clinical pattern of stroke and the angiographic distribution of cerebral atherosclerosis in Chinese are different from those in Caucasians. Pathological data from autopsy studies are lacking. The intracranial and extracranial arteries supplying the brains of 114 consecutive Chinese patients undergoing autopsy in a regional general hospital were examined by computer-assisted morphometric analysis under a microscope as well as by macroscopic grading for atherosclerotic narrowing. The severity was correlated with various atherosclerosis-related factors. Atherosclerosis of the intracranial cerebral vessels was more severe than that of the extracranial vessels. The distal branches of the intracranial vessels were also commonly involved. Hypertension and diabetes mellitus were identified as factors associated only with intracranial atherosclerosis (p < 0.001), whereas ischemic heart disease was associated with atherosclerosis in both the intracranial (p < 0.001) and extracranial (p = 0.012) vessels. Smoking was associated with narrowing of the extracranial vessels only (p = 0.0054). Compared with figures from Caucasian and Japanese populations, the extent of intracranial atherosclerosis is much more severe in Hong Kong Chinese, whereas atherosclerotic narrowing of the extracranial carotid artery is less severe in Hong Kong Chinese than in Caucasians.

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