Circularly polarized perovskite luminescence with dissymmetry factor up to 1.9 by soft helix bilayer device

Metal halide perovskites are exceptional light-emitting materials. Endowing perovskites with circularly polarized luminescence (CPL) offers great promise for innovative applications, but the existing strategies are inefficient in acquiring large dissymmetry factor (g(lum)), high quantum efficiency, and long-term stability. Here, we demonstrate bright and stable CPL with a glum value up to 1.9 from perovskites in chiral liquid crystal (LC)-based soft helix devices featuring a bilayer architecture. The incorporation of an optimized polymer of polyacrylonitrile (PAN) in the bilayer device remarkably improves luminescent efficiency and stability of perovskite, while perfectly preserving optical and stimuli-responsive characteristics of chiral LCs. The resulting bilayer devices allow systematical composition engineering of both perovskite and soft helix and enable full-color CPL with high g(lum) values. Moreover, CPL-active devices with diverse graphical patterns and reversible thermal -switching behavior can further expand the scaffold for cryptology and anti-counterfeiting applications.

Automated summary

This study demonstrates the achievement of high-brightness and stable circularly polarized luminescence in chiral liquid crystal-based soft helix devices with a bilayer structure. The introduction of an optimized polyacrylonitrile polymer significantly improves the luminescent efficiency and stability of perovskites while preserving the characteristics of chiral liquid crystals. This technique enables the fabrication of full-color circularly polarized luminescence devices with high g(lum) values.