Pseudo-Homologue Doping Strategy for Afterglow Materials.

Impurities in organic phosphorescent materials have caused extensive discussions in recent years. In this work, we demonstrate the impressive afterglow of commercial benzene-carboxylic acid (BCA) derivatives are attributed to trace impurities identified as biphenyl carboxylic acid derivatives. One of the impurities even induces detectable phosphorescence when the doping ratio is as low as 0.1 ppm (molar ratio). Inspired by the structural similarity between impurities and the main component, we propose a pseudo-homologues strategy for constructing afterglow materials. Based on this model, several groups of compounds are used to prepare 275 doped samples. Surprisingly, pseudo-homologues exhibit a markedly higher success rate for afterglow (73.3%) compared to that of other samples (6.5%). This structural model offers new perspectives for the construction of dual-component afterglow materials.