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Halide perovskite materials are emerging as a new promising semiconductor display material owing to their excellent optical and electrical properties. Highly efficient blue perovskite light‐emitting diodes (PeLEDs) are the basis for full‐color displays and solid‐state lighting applications, but their efficiency and stability still lag far behind the red and green analogs. This review focuses on the key effect factors and novel strategies for blue emission PeLEDs. In detail, first effective strategies to obtain blue emission perovskite are discussed, and then the recent progress and strategies in blue emission PeLEDs, including the physical properties and significant improvements based on different structural perovskite materials are systematically elucidated. Finally, the main challenges relating to efficiency, stability, lead toxicity, and fabrication techniques in blue emission PeLEDs are summarized, and the promising research avenues in the future are discussed. [ABSTRACT FROM AUTHOR]

Metal halide perovskite (MHP) materials have shown great advantages for the next‐generation optoelectronic devices, especially for light‐emitting diodes (LEDs), on account of their outstanding photoelectric properties and facile solution processability. However, the performances of red perovskite LEDs (PeLEDs) are not ready for commercialization, presumably due to the instability both of the emission spectra and operation conditions, and the toxicity of lead ions. In this review, the structures, physical properties, and preparation approaches of red emissive perovskite materials are first introduced, including 3D bulk perovskites, 2D and quasi‐2D perovskites, and colloidal perovskite nanocrystals (NCs). In addition, several strategies that contribute to the recent development and achievement of red PeLEDs are summarized in detail, mainly involving component engineering, dimension, and phase distribution modulation, ligand engineering, additive engineering, interfacial engineering, and strategies for the light out‐coupling device structure. Moreover, the challenges and corresponding solutions are discussed from three aspects of spectral stability, operational stability, and lead‐free red PeLEDs. Finally, the conclusion and outlook on the promising future of the red PeLEDs are raised. [ABSTRACT FROM AUTHOR]

Orientational ordered soft matter possessing diverse microstructures has become a focal point of scientific research and technological exploration, thanks to its advancements in serving as an indispensable optical platform enabling propagation of light with multidimensional and manipulatable states. Herein, a facile way is developed to manipulate the in‐plane light beam transition dynamics by harnessing a time‐variable nematic liquid crystal (NLC) film through the electrical‐field‐induced topological defects. The results show that the dynamic change of optical branched flow is associated with the growth in the correlation length of optical potential and the reduction in the density of topological defects. The optical branching can continuously transform to deterministic and tunable beam steering at the low‐defect‐density regime through annihilation kinetics of defects. The explored soft matter system provides an excellent planar platform for the fundamental physics of light interacting with topological defects and may offer new perspectives for novel optics elements toward the applications of soft matter photonics. [ABSTRACT FROM AUTHOR]