Towards Chiral Lasing from All-Solution Processed Flexible Perovskite Nanocrystal-Liquid Crystal Membrane.

Circularly polarized (CP) coherent light sources are of great potential for various advanced optical applications spanning from display/imaging to data processing/encryption and quantum communication. Here we report the first demonstration of CP amplified spontaneous emission (ASE)/lasing from a free-standing and flexible membrane device consisting of perovskite nanocrystals (PNCs) and cholesteric liquid crystal layers sandwiched within a Fabry-Perot cavity architecture. The chiral liquid crystal cavity enables the generation of CP light from the device. The device is completely solution-processable, and displays CP ASE with record dissymmetry factor (g lum ) as high as 1.4, which is 3 orders of magnitude higher as compared with g lum of CP luminescence of chiral ligand-capped colloidal PNCs. The device exhibits ultra-flexibility as the ASE intensity remains unchanged after repeated 100 bending cycles and it is stable for more than 3 months with 80% of its original intensity. Furthermore, the ultra-flexibility enabled the generation of ASE from various objects of different geometric surfaces covered with the flexible perovskite membrane device. This work not only demonstrates the first CP ASE from PNCs membrane with extremely high g lum but also opens the door toward the fabrication of ultra-flexible, extremely stable, and all solution-processable perovskite chiral laser devices. This article is protected by copyright. All rights reserved.