Multi-responsive circularly polarized luminescence micro-patterns with high figure of merit towards multi-dimensional data encoding

Abstract

Circularly polarized luminescence (CPL) materials are emerging as promising tools for multi-dimensional data encoding due to their inherent chiroptical information dimension, facile reading and reduced cost. In classic cholesteric liquid crystal (LC) systems, a giant dissymmetry factor of CPL (g_lum > 1.2) can be achieved based on the selective transmission mechanism, however, this comes with a nearly 50 % loss in luminescence efficiency (φ), resulting in lower figure of merit (FOM). Developing novel CPL materials with high g_lum and FOM values, multi-responsivity, and arbitrary patterning ability is crucial for meeting the demands of practical applications. Herein, we proposed a general twisted-stacking strategy to break the bottleneck for CPL materials and unexpectedly achieving 95 % luminescence efficiency, g_lum of 1.28 and high FOM value up to 1.22, much higher than most reported CPL systems. The bottom-layer photo-polymerizable nematic liquid crystal (NLC) endows not only excellent polarized luminescence with multi-responsivity but also arbitrary patterning capabilities. Simultaneously, the top-layer transparent oriented poly (vinyl alcohol) (PVA) layer serves as the phase retardation, resulting in the generation of CPL with a high g_lum, while φ is preserved without diminishing. By applying external light, voltage and heat, the CPL signal within the micropatterns can be precisely regulated, allowing for the implementation of high-level anti-counterfeiting and multi-dimensional information encryption.