Precise Vibration Decoupling and Matrix Rigidification: A Dual Locking Strategy for Highly Efficient Photoluminescence

ABSTRACT Suppressing nonradiative decay is crucial for achieving high photoluminescence quantum yields (PLQYs) in light‐emitting materials. Although high‐performance optical materials have been explored in the past decades, the specific dissipation pathways of their nonradiative channels remain unclear. This work unveils the energy dissipation mechanisms of excited states at the microscopic molecular level, achieving singlet‐state vibration decoupling through intramolecular through‐space charge transfer (TSCT), thereby promoting efficient fluorescence emission. Moreover, the rigid environment and multiple noncovalent interactions (e.g., hydrogen bonding and electrostatic complementarity) provided by the polymer matrix effectively restrain the vibrational motion of the chromophores, creating favorable conditions for triplet‐state room‐temperature phosphorescence (RTP). Experimental and theoretical results demonstrate that TSCT‐induced vibration decoupling is key to the high‐efficiency fluorescence of 1 Np, while the planar rigid structure of TPNp dispersed in the polymer enables long‐lived blue RTP with a lifetime of τ P = 1.96 s. This study systematically elucidates the multipathway energy dissipation mechanisms in photon radiative decay and provides a refined theoretical framework for a deeper understanding of excited‐state dynamics in photo‐functional materials.