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Polarization emission from halide perovskite is expected to bring a lot of benefits for next‐generation displays, such as cost down, wide color gamut, and structure simplification. In this work, strong linearly polarized luminescence from emissive halide perovskites modulated by photoaligned azobenzene dye AD1 is demonstrated. The azobenzene dye functionalized halide perovskite thin films not only exhibit exceptionally high degree of polarization (DOP) of 86.2–93.1% for red, green, and blue emission, but also promise an improved environmental stability originating from the hydrophobic nature of the azobenzene dye. When these perovskite/AD1 composite films are applied in liquid crystal display panels to replace the conventional thick polarizer, the energy efficiency can be doubled and the color gamut can be extended to >120% NTSC. Furthermore, the AD1 functionalized strategy is successfully employed to generate linearly polarized electroluminescence from an inverted perovskite light‐emitting diode, showing a high DOP of 47%. [ABSTRACT FROM AUTHOR]

Electroluminescent devices based on metal halide perovskites have attracted extensive attention owing to their high external quantum efficiency, excellent color purity, and inexpensive solution process. So far, extensive efforts have been made to improve the efficiency of the monochromatic perovskite light‐emitting diodes (LEDs). However, multicolor perovskite‐based LEDs are seldom studied. Here, an individual device capable of multicolor emission in response to the passage of external electric bias is demonstrated. With the rational design of the energy band alignment and control of the carrier transport property, color‐tunable electroluminescent devices based on inorganic halide perovskite and chalcogenide quantum‐dots are fabricated with a wide color tuning range, high color reversibility, and ultrafast color switching. The mechanism of chromaticity tuning is investigated and is explained by the shift of the exciton recombination zone with the driving voltage. The presented work will impact scientific communities by encouraging the manufacture of cost‐effective, high‐resolution, and full‐color displays and human‐centric lighting. [ABSTRACT FROM AUTHOR]