Circularly polarized luminescent liquid crystal materials with aggregation- induced emission functionality

Circularly polarized light is a type of light in which the endpoint trajectory of the light vector forms a circle. During its propagation,the magnitude of the light vector remains constant while the vibration direction changes along with phase. Typically,unpolarized light is first converted to linearly polarized light through a polarizer and then transformed into left-handed or right- handed circularly polarized light using a quarter-wave plate. However,this physical process results in an energy loss higher than 50% for circularly polarized light. By introducing aggregation-induced emission (AIE) properties into chiral liquid crystal molecules,circularly polarized light can be directly obtained with a high fluorescence quantum efficiency and a large asymmetric factor,thereby achieving effective reduction of energy loss. Consequently,AIE chiral liquid crystals have gained increasing attention from researchers in relevant fields. This review summarizes the recent progress in this field,focusing on the design and synthesis of chiral liquid crystal molecules modified with AIE luminophores and the doping of chiral AIE molecule systems into nematic liquid crystal phases. The influence of the chemical structure design of AIE liquid crystal molecules and the formation of aggregates on circularly polarized luminescence and AIE performance are discussed. Finally,the existing challenges and opportunities for this new optical material are prospected.