Stabilizing high-efficiency perovskite solar cells (PSCs) at operating conditions remains an unresolved issue hampering its large-scale commercial deployment. Here, we report a star-shaped polymer to improve charge transport and inhibit ion migration at the perovskite interface. The incorporation of multiple chemical anchor sites in the star-shaped polymer branches strongly controls the crystallization of perovskite film with lower trap density and higher carrier mobility and thus inhibits the nonradiative recombination and reduces the charge-transport loss. Consequently, the modified inverted PSCs show an optimal power conversion efficiency of 22.1% and a very high fill factor (FF) of 0.862, corresponding to 95.4% of the Shockley-Queisser limited FF (0.904) of PSCs with a 1.59-eV bandgap. The modified devices exhibit excellent long-term operational and thermal stability at the maximum power point for 1000 hours at 45°C under continuous one-sun illumination without any significant loss of efficiency.

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Polyhedral oligomeric silsesquioxane (POSS)‐hybrid polymers have been successfully employed as functional inorganic–organic hybrid materials for various applications due to their well‐determined structures. The past 6 years has witnessed growing interest in the rational design and synthetic approaches for POSS‐hybrid polymers, driven by the adoption of controlled living radial polymerization and click chemistry. This review addresses developments in the precise manipulation of POSS building blocks via atom transfer radical polymerization, reversible addition–fragmentation chain transfer, and click chemistry. Not only are the structures of POSS‐hybrid polymers tunable in terms of chemical composition, molecular weight, and polydispersity, but they are also controllable in sequential and hierarchical chain topology. Finally, some representative cutting‐edge applications of POSS‐hybrid polymers, including biomedical and energy‐related materials, fabrication of nanostructures, and functional surface coating materials, are highlighted.

In nature, the fibrils of awns can make open-close motion in response to humidity change. Shorebirds can suck water droplets by repeatedly open-close motion of the beaks. Through the fusion of those inspirations, we report a directional droplet delivery device in response to humidity. The hydrogel-actuated switch was fabricated through the integration of polyacrylic acid hydrogel, cellulose membrane and superhydrophilic copper wires. It can realize directional droplet delivery. In open state, the droplet was propelled directionally towards the tip-site of the conical channel by virtue of Laplace pressure difference. When the switch shifted to be close and the channel turned into the parallel, the droplet was pinned due to the disappearance of Laplace pressure difference. The switch for directional liquid delivery can attract broad interests in the field of microfluidics, droplets manipulation, etc.