Perovskite solar cells (PSCs) have achieved high power conversion efficiency on the lab scale, rivaling the other commercialized photovoltaic technologies. However, stability issues have made it difficult for PSCs to achieve comparable or practical lifetimes in outdoor applications. Here, three different types of hot melt films (polyurethane, PU; polyolefin, POE; and ethylene vinyl acetate, EVA) together with glass sheets are employed to encapsulate printable PSCs. The influence of thermal stress and the encapsulation (lamination) process on cell performance is investigated. It is found that POE and EVA, which are the typical encapsulants for silicon and thin film solar cells, are not suitable for the encapsulation of PSCs due to a high laminating temperature (>130 °C) or corrosion of the perovskite absorber. By contrast, encapsulation with PU can be carried out at a relatively mild temperature of 80 °C, and significantly enhance the thermal stability of the cells. When this encapsulation method is applied to largearea (substrate area 100 cm 2 ) printable PSC submodules, the submodules can maintain 97.52% of the initial efficiency after 2136 h under outdoor conditions (location: 39°19′48″N 114°37′26″E). This work demonstrates the potential of industrially relevant encapsulation techniques to enable the commercial viability of PSCs.

Metal nanoparticles (NPs) dispersed on a high-surface-area support are normally used as heterogeneous catalysts. Recent in situ experiments have shown that structure reconstruction of the NP occurs in real catalysis. However, the role played by supports in these processes is still unclear. Supports can be very important in real catalysis because of the new active sites at the perimeter interface between nanoparticles and supports. Herein, using a developed multiscale model coupled with in situ spherical aberration-corrected (Cs-corrected) TEM experiments, we show that the interaction between the support and the gas environment greatly changes the contact surface area between the metal and support, which further leads to the critical change in the perimeter interface. The dynamic changes of the interface in reactive environments can thus be predicted and be included in the rational design of supported metal nanocatalysts. In particular, our multiscale model shows quantitative consistency with experimental observations. This work offers possibilities for obtaining atomic-scale structures and insights beyond the experimental limits.

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The shape of metal nanoparticles (NPs) is one of the key factors determining their catalytic reactivity. Recent in situ TEM observations show that dynamic reshaping of metal NPs occurs under the reaction conditions, which becomes a major hurdle for fully understanding catalytic mechanisms at the molecular level. This Minireview provides a summary of the latest progress in characterizing and modeling the equilibrium shape of metal NPs in various reactive environments through the joint effort of state‐of‐the‐art in situ environmental transmission electron microscopy experiments and a newly developed multiscale structure reconstruction model. The quantitative agreement between the experimental observations and theoretical modeling demonstrate that the fundamental mechanism of the reshaping phenomenon is driven by anisotropically changed surface energies under gas adsorption. The predictable reshaping of metal NPs paves the way for the rational design of truly efficient nanocatalysts in real reactions.