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Circularly polarized luminesce (CPL) materials are crucial for various applications, including display devices and bionics. However, existing CPL materials face difficulties in simultaneously meeting large luminescence asymmetry factors (glum), high photoluminescence quantum yields (PQY), and long lifetime. Here, a simple strategy to prepare a series of high‐performance CPL liquid crystal copolymers is constructed by triplet–singlet Förster‐resonance energy transfer (TS‐FRET). A series of chiral liquid crystal copolymers are successfully synthesized by copolymerizing phosphorescent donor bearing chiral cholesterol mesogen with fluorescence acceptor bearing naphthalimide chromophore. The introduction of the naphthalimide component promotes the formation of twist grain boundary smectic‐A phase (TGBA*) and behaves distinctive selective reflective effect. An effective TS‐FRET process occurs in the two components of copolymers, and dual emission characteristics of thermally activated delayed fluorescence and room‐temperature phosphorescence are observed in the copolymer films. When the naphthalimide content of copolymer is 10%, the luminescence lifetime can achieve 83.0 ms. As the naphthalimide content increases, the glum initially increases and subsequently decreases, reaching a maximum of −1.15. In addition, the copolymer films possess enhanced photoluminescence quantum yield by TS‐FRET with a maximum value of 68%. The application of copolymers in information security is also explored. [ABSTRACT FROM AUTHOR]

Linearly polarized luminescent (LPL) materials have garnered significant interest for their applications in linearly polarized organic light-emitting diodes, displays and so forth. However, the majority of previous reports have mainly focused on linearly polarized fluorescent materials. Linearly polarized phosphorescent materials have been rarely reported mainly because of their unstable triplet excitons and difficulties in orientation control of phosphorescent chromophores. Herein, side-chain polymers PMDFMmC (m = 0, 2, 4, and 6) with room-temperature phosphorescence (RTP) are synthesized. The oriented PMDFMmC films are then prepared by a template-assisted method. By changing the flexible spacer length of PMDFMmC, their photo-physical properties are well regulated. As the flexible spacer length increases, the glass transition temperature (Tg) of polymers decreases from 110 °C to 58 °C, the phosphorescence lifetime decreases from 629.8 ms to 476.8 ms, and the phosphorescence color changes from orange-red to yellow. All oriented PMDFMmC films also show good linearly polarized phosphorescent properties. Meanwhile, as the flexible spacer length increases, the dichroic ratio and polarization ratio values gradually enhance. Using oriented PMDFM6C films, linearly polarized phosphorescence dichroic ratio and polarization ratio values of 14.8 and 0.87, respectively, can be achieved. [ABSTRACT FROM AUTHOR]

Circularly polarized luminescent (CPL) materials have significant promising applications in organic light‐emitting diodes, asymmetric synthesis, and other fields. However, due to the instability of triplet‐state excitons, how to achieve an effective combination of CPL with room‐temperature phosphorescence (RTP) remains a formidable challenge. Here, a simple and feasible method for constructing polymer‐based CPRTP materials is proposed by preparing chiral phosphorescent liquid crystals through copolymerization. A series of RTP chiral liquid crystal copolymers are successfully synthesized by copolymerizing phosphorescent monomer bearing chiral cholesterol mesogen with phosphorescent monomer bearing dibenzofuran chromophore. Due to the introduction of chiral cholesterol mesogen, copolymers can form chiral smectic C‐phase liquid crystals. Utilizing their selective reflection characteristic, efficient CPRTP is achieved, with a glum value of up to −1.6 × 10−2. In addition, both components in copolymers exhibit RTP properties and show significant differences in phosphorescence color and lifetime. By changing the composition of copolymers, the regulation of their phosphorescence properties is successfully achieved. As a result, multicolor‐tunable and time‐dependent CPRTP materials are successfully prepared. [ABSTRACT FROM AUTHOR]