Long‐Lived and High‐Brightness Room‐Temperature Phosphorescence Materials for Illumination

ABSTRACT Polymer‐based RTP systems with planar guests exhibit outstanding luminescence performances, while long lifetimes could only be realized at low doping concentrations due to aggregation‐caused quenching. This inherently limits brightness by suppressing the population of triplet excitons. Development of high‐brightness and long‐lived room‐temperature phosphorescence (RTP) materials remains a formidable challenge that severely limits their potential for illumination. Given this, a molecular design strategy centered on geometric control is proposed in this contribution. A twisted molecular geometry was constructed by integrating a tetrahedral triphenylphosphine moiety into planar carbazole, leading to effective suppression of its self‐aggregation in the polymer host, even at high doping levels. As anticipated, the developed RTP materials achieved a long lifetime of 1868 ms along with a remarkable brightness of 1.08 × 10 4 mcd/m 2 , representing an over 2000‐fold enhancement in RTP brightness compared to the planar carbazole‐containing analogs. The direct application of these high‐brightness and long‐lived RTP materials in illumination was further explored in this work, advancing the prospects for practical phosphorescence illumination systems.