Mechanically Tunable Circularly Polarized Luminescence of Liquid Crystal‐Templated Chiral Perovskite Quantum Dots

Structural color coatings with brilliant color is important in practical applications, such as aesthetic decoration, bionic skins, colorimetric sensors, and other color‐related fields. However, the intrinsic conflict between fast self‐assembly and bright structural color hinders their widespread applications. Here, cholesteric liquid crystal elastomer (CLCE) coatings with brilliant color and mechanochromic response are developed by spraying the cholesteric liquid crystal (CLC) paints followed by evaporation‐induced self‐assembly (EISA) and photocuring. The Marangoni flow within the paints, which drives the orientation of liquid crystal molecules along the flow track in the EISA process, is found to be crucial for achieving both rapid self‐assembly time (60 s) and high reflectivity structural color (42%). The as‐prepared CLCE coatings present uniform structural colors, circularly polarized reflection, and mechanochromic response. Several proofofconcept applications are also demonstrated, including patterned CLCE coatings on flat substrates, fully covered CLCE coatings on 3D objects, and non‐spectral colors via additive mixing method. The research disclosed herein provides unprecedented levels of efficiency and reliability for preparing structural color coatings.

Cholesteric Liquid Crystal Elastomer Coatings with Brilliant Structural Colors and Mechanochromic Response Fabricated by Spray Deposition

Li,

Chen,

et al. 2024

Circularly Polarized Organic Ultralong Room‐Temperature Phosphorescence: Generation, Enhancement, and Application

Liu,

Zhou,

Tang

et al. 2024

Circularly polarized luminescent (CPL) materials have garnered tremendous attention owing to their expanded optical properties beyond emission wavelength and intensity. Among these, the emerging circularly polarized organic ultralong room‐temperature phosphorescence (CP‐OURTP) materialsdemonstrating elegant and distinct features are of significant importance for their extended emission lifetime, which represent a novel frontier in research with promising scientific and technological applications across diverse fields. This review systematically outlines the traditional strategies to achieve CP‐OURTP including organic crystals, copolymerization, host–guest doping, a combination of the copolymerization and host–guest doping, spinning and twisting technology, and supramolecular polymer assembly. Importantly, the recent significant progress of CP‐OURTP in the chiral soft materials, such as liquid crystals (LCs) involving lyotropic LCs (cellulose nanocrystals, CNCs) and chiral thermotropic LCs (cholesteric LCs and chiral LC elastomers), is showcased. Finally, the practical applications of CP‐OURTP materials are summarized, and the review concludes with the perspectives on the current challenges and future opportunities for CP‐OURTP materials. This review aims to inspire the further innovations in the fabrication of advanced CP‐OURTP materials and enrich their promising applications.

Energy Transfer for Constructing Circularly Polarized Luminescence Materials: Recent Progress and Future Prospects

Zhang,

Zhong,

Yang

et al. 2024

Circularly polarized luminescence (CPL) materials hold significant promise in multidisciplinary fields such as circularly polarized organic light‐emitting diodes, biological probes, data storage, and information encryption. However, these cutting‐edge applications also put forward higher requirements for the design of CPL materials, requiring large dissymmetry factor and high emission quality. For this purpose, diverse approaches have been explored to generate and enhance CPL emission. Among them, energy transfer (ET) strategy stands out as it can be readily implemented in a wide range of CPL materials. The present work overviews latest advances in energy transfer for generating and modulating CPL, involving small organic molecules, polymers, metal complexes, liquid crystals, as well as new‐emerging chiral luminescent materials. It is anticipated that the review article will garner increased attention toward energy transfer systems and facilitate the advancement of CPL materials.