Carbon Dots-in-Zeolite via In-Situ Solvent-Free Thermal Crystallization: Achieving High-Efficiency and Ultralong Afterglow Dual Emission

Organic afterglow materials are highly desirable for optoelectronic applications, but they usually suffer from complex preparation process, low quantum efficiency, and short lifetime due to the ultrafast deactivation of the highly active excited states involved. Here, we succeeded in achieving solventfree thermal syntheses of high-efficiency afterglow CDs@zeolite composite materials by simply grinding the solid raw materials of zeolite and precursor CDs at room temperature, followed by thermal crystallization. This method afforded maximum embedding of CDs into growing zeolite crystals, as well as strong host-guest interaction to surpass the nonradiative transition of CDs, thus producing composite materials with ultralong dual emission of thermally activated delayed fluorescence and room temperature phosphorescence with a record high lifetime of 1.7 and 2.1 s, respectively, and the quantum yield of 90.7%. Furthermore, in a preliminary experiment, we applied the composite materials in alternatingcurrent light-emitting diode supplementary lighting, which exhibited a promising potential in optoelectronic applications.