The authors investigate how chiral ligands attached to perovskite nanocrystal (PNC) surfaces structurally distort the perovskite lattice. Chiral electro‐optical properties of the resulting PNCs are demonstrated through the fabrication of a circularly polarized light (CPL) detector with a discrimination of up to 14% between left‐ and right‐handed CPL. Both experimental and electronic‐structure‐based simulations are combined to provide insights into the interactions (both structural and electronic) between chiral organic ligands and PNCs. The major finding is a centro‐asymmetric distortion of the surface lattice that penetrates up to five atomic unit cells deep into the PNCs, which is the likely cause of the chiral‐optical properties. Spin‐polarized transport through chiral‐PNCs results from the chiral‐induced spin selectivity effect and amplifies the discrimination between left and right‐handed CPL as is experimentally demonstrated in the detectors.

However, even with the use of nanoscale materials, the large volume changes associated with charging and discharging cause the fragmentation of the anode material, [2] decreasing their capacities, and cycling lifetimes. The coating and doping of anode nanomaterials are among the various methods proposed to address this problem. [3] However, these methods are complex and expensive, and the overlayer coated on the anode nanomaterials may hinder the fast transport of carrier ions. Another approach based on the reaction between an anode material and electrolyte has also been reported. [4] This method induces the spontaneous restructuring of a bulk anode material into a 3D porous nanostructure during battery cycling with a glyme-based electrolyte [4b-e] . Although the short diffusion distance in thus-formed nanostructure is beneficial for improving the rate performance of the anode, its energy capacity still rapidly decreases with increasing current rate (C-rate). [3a,b,5] This indicates that a strategy based on reducing the diffusion distance alone is not sufficient to simultaneously improve the energy capacity, rate capability, and cycling stability of alloying anodes.To determine another variable governing the kinetics of carrier-ion diffusion at high C-rates, it is necessary to investigate why the practical capacity of the anode decreases with It is challenging to develop alloying anodes with ultrafast charging and large energy storage using bulk anode materials because of the difficulty of carrierion diffusion and fragmentation of the active electrode material. Herein, a rational strategy is reported to design bulk Bi anodes for Na-ion batteries that feature ultrafast charging, long cyclability, and large energy storage without using expensive nanomaterials and surface modifications. It is found that bulk Bi particles gradually transform into a porous nanostructure during cycling in a glyme-based electrolyte, whereas the resultant structure stores Na ions by forming phases with high Na diffusivity. These features allow the anodes to exhibit unprecedented electrochemical properties; the developed Na-Bi half-cell delivers 379 mA h g −1 (97% of that measured at 1C) at 7.7 A g −1 (20C) during 3500 cycles. It also retained 94% and 93% of the capacity measured at 1C even at extremely fast-charging rates of 80C and 100C, respectively. The structural origins of the measured properties are verified by experiments and first-principles calculations. The findings of this study not only broaden understanding of the underlying mechanisms of fast-charging anodes, but also provide basic guidelines for searching battery anodes that simultaneously exhibit high capacities, fast kinetics, and long cycling stabilities.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/adma.202201446.

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Solution-processed small-molecule organic light-emitting diodes (OLEDs) are regarded as next-generation flat-panel displays and solid-state lighting sources due to low material loss and a simple device fabrication process. However, they still suffer from low device efficiency and severe efficiency roll-off. Here, molecular-scale strategies are proposed to achieve highly efficient solutionprocessed small-molecule OLEDs with reduced efficiency roll-off. By combining experiments with ab initio and molecular dynamics simulations, it is shown that an acetylacetonate group in a phosphorescent dopants lowers the dipole moment and molecular interaction energy of dopants, reducing dopant aggregation and increasing charge carrier transport. Furthermore, a chargebalance assistant molecule is incorporated in the mixed-host emitting layer to increase the balance of charge carrier transport and to broaden the exciton recombination zone in the center of the emitting layer. The resulting OLEDs have a current efficiency (CE) of 103.7 cd A −1 , which is the highest yet reported in solution-processed OLEDs, and low efficiency roll-off (CE = 99.68 cd A −1 at a luminance L EL = 100 cd m −2 , and CE = 75.00 cd A −1 at L EL = 1000 cd m −2) even with the simplified device architecture. It is expected that this strategy will advance the feasibility of commercialization of low-cost high-efficiency OLEDs.