Precise Modulation of Circularly Polarized Luminescence via Polymer Chiral Co‐assembly and Contactless Dynamic Chiral Communication

Circularly polarized luminescence (CPL) plays a pivotal role in cutting‐edge display and information technologies. Currently achieving precise color control and dynamic signal regulation in CPL still remains challenging due to the elusory relationship between fluorescence and chirality. Inspired by the natural mechanisms governing color formation and chiral interaction, we proposed an addition‐subtraction principle theory to address this issue. Three fluorene‐based polymers synthesized by Suzuki polycondensation with different electron‐deficient monomers exhibit similar structures and UV‐vis absorption, but distinct fluorescence emissions due to intramolecular charge transfer. Based on this, precise‐color CPL‐active films are obtained through quantitative supramolecular co‐assembly directed by addition principle. Particularly, an ideal white‐emitting CPL film (CIE coordinates: (0.33, 0.33)) is facilely fabricated with a high quantum yield of 80.8% and a dissymmetry factor (glum) of 1.4 × 10−2. Structural analysis reveals that the ordered stacking orientation favors higher glum. Furthermore, to address the dynamically regulated challenge, the comparable subtraction principle is proposed, involving a contactless chiral communication between excited and ground states. The representative system consisting of as‐prepared fluorene‐based polymers and chirality‐selective absorption azobenzene (Azo)‐containing polymers is constructed, achieving CPL weakening, reversal, and enhancement. Finally, a switchable quick response code is realized based on trans‐cis isomerization of Azo moiety.