Spontaneous Alignment of Liquid Crystals for Dual‐Mode Smart Windows with Active and Passive Control Functions

Abstract Liquid crystal‐based smart windows, easily manipulating sunlight blocking/transmission using a switch according to the user's request and environmental conditions, represent a primary research hotspot resource of great interest. However, the challenges of efficient liquid crystal alignment technology and multifunctional integration/multi‐mode driving limit the further widespread application of these smart windows. In this work, a facile strategy for fabricating dual‐mode smart windows is presented, utilizing the self‐alignment effect of trace ionic liquid‐doped thermotropic liquid crystals and eliminating the need for conventional orientation layers. This technology offers a streamlined approach to energy‐efficient liquid crystal‐based smart window fabrication. The resulting windows demonstrate reversible modulation of optical transmittance (80–15%) and haze (2–78%) in response to both passive to temperature and active to electric fields, enabling adaptive solar management and dynamic privacy control. It highlights the potential of ionic liquid‐doped liquid crystals as a versatile platform for next‐generation adaptive building materials and has imparted a new strong impetus for the further development of liquid crystal technology.