Boric Acid-Activated Room-Temperature Phosphorescence and Thermally Activated Delayed Fluorescence for Efficient Solid-State Photoluminescence Materials

摘要

The construction of highly luminescent solid-state materials with longlivedafterglow through a straightforward method is promising but still achallenging task. Herein, a heat-treatment strategy is proposed to embedlevofloxacin (Lev) in the matrix of boric acid (BA) to produce a complex witha photoluminescence quantum yield of 63.8% and an emission lifetime of0.74 s (afterglow: >5 s). Detailed investigations suggest that the uniquephotophysical properties of the complex are attributed to the confinementeffect of BA matrix to Lev, which reduces the probability of nonradiativerelaxation and activates the radiative decays to result in the promoted emissionefficiency. In addition, thermally activated delayed fluorescence is alsoactivated due to the alteration of the π transition of Lev by the formation ofboron–carbon bonds. The emission color and lifetime are also modulatedthrough controlling the synthetic conditions, which endow their applicationsboth in light-emitting diodes and information encryption. Thus, thepresent results are significant for the construction of solid-state luminescentmaterials, including fluorescence and room-temperature phosphorescence,and also provide a solid and universal theory to clarify their detailedemission profiles.