Circularly polarized luminescence in chiral nematic liquid crystals: generation and amplification

Abstract

Circularly polarized luminescent materials have reached a thriving stage due to their potential applications in various research fields. However, the most important parameter of circularly polarized luminescence, luminescence dissymmetry factor (g_lum), is unsatisfactory to date, particularly for organic small molecules. Thus, obtaining large g_lum values is an emergent and critical challenge in the CPL research field, and various strategies have consequently been proposed, including supramolecular self-assembly or co-assembly, energy transfer or charge transfer hybrid chiral systems, aggregation-induced emission chiral luminophores, and so forth. Nevertheless, among all these strategies, chiral nematic liquid crystals (N*LCs) possess incomparable advantages in acquiring high g_lum values, because of their unique optical properties and excellent generality. In this review, we systematically review the recent progress of CPL-active N*LCs and provide a short perspective on their further applications. We envisage that N*LCs will play a more and more important role in the CPL research field and this review will attract more researchers to this field.