Multi‐Stimuli Responsive Phosphate Hybrids With Visible‐Light‐Excited Dual‐Mode Afterglow Toward Multifunctional Applications

ABSTRACT Dual‐mode afterglow emission is a notable photoluminescent phenomenon in which materials exhibit prolonged luminescence via thermally activated delayed fluorescence (TADF) and phosphorescence. Developing such dual‐mode materials through a simple preparation process is inherently difficult and presents technical hurdles. Here, we fabricate a series of afterglow hybrids through thermal treatment of dihydrogen phosphates with fluorescein derivatives. A hybrid composed of Al(H 2 PO 4 ) 3 and fluorescein (FL) show visible‐light‐excited green afterglow lasting for 5 s at 298 K and yellow afterglow lasting for 11 s at 243 K. Additionally, introducing heavy atoms into fluorescein induces afterglow hybrids to achieve dual‐mode afterglow emission at room temperature. Notably, the afterglow hybrids exhibit wider singlet‐triplet energy gaps (ΔE ST > 0.3 eV). Various applications such as afterglow thermometers, 7D encryption, model painting, latent fingerprint identification, and gastric mucosal staining can be realized through solution process, driven by the high luminescent intensities, multicolor afterglow, and temperature tunability. Our hybridization strategy not only discovered a novel matrix for preparing afterglow materials but also expanded its applications in bio‐imaging and multi‐stimuli response.