Circularly polarized luminescence in chiral nematic liquid crystals based on photochromic molecules

Circularly polarized luminescence (CPL) has emerged as a focal point in luminescent materials research, reflecting a growing field of study. Responding to the demand for practical applications across diverse sectors, there is a critical need for CPL materials with high luminescence dissymmetry factors (g lum) and adjustable optical performance, driving the development of novel materials and methodological approaches. Chiral nematic liquid crystals (N*-LCs) have attracted significant attention as promising candidates for producing high-performance CPL materials due to their ability to exhibit enhanced g lum and modulate circularly polarized light. This review comprehensively presents the stimuli-responsive CPL properties, utilizing N*-LCs as chiral templates doped with various photochromic compounds, particularly azobenzene, spiropyran (SP), diarylethene and overcrowded alkene. By elucidating the dynamic interplay between molecular structure, supramolecular organization, and optical response, it offers a profound understanding of the stimuli-responsive CPL behaviors. Additionally, the review also explores the multifaceted applications of photochromic N*-LCs materials, spanning advanced display technologies, optical data storage, and beyond. By examining diverse avenues for leveraging their unique optical properties, it highlights their pivotal role in driving innovation across photonic applications, facilitating transformative advancements in the field.