Energy Transfer Mediated Enhancement of Room-Temperature Phosphorescence of Carbon Dots Embedded in Matrixes

Energy transfer (EnT) is a commonly used study method in the research of organic luminescent materials, but rarely reported in carbon dots (CDs) related work. In this work, an efficient EnT mediated method for enhancing room temperature phosphorescence (RTP) of CDs through embedding pure phosphorescent CDs into afterglow matrixes is brought up for the first time. In such design system, the emission intensity, phosphorescence lifetime, and emission time of CDs are prolonged significantly, and all the CD-based materials emit more than 20 s phosphorescence visible to eye after the ultraviolet excitation. The overlap between the phosphorescence excitation spectra of CDs and the afterglow emission spectra of afterglow matrixes reveal the possibility of the EnT from matrixes to CDs, and the phosphorescence emission and lifetimes spectra of CDs, matrixes, and CDs@matrix further verify the presence of EnT process. Besides, phosphorescent CDs embedded in nonafterglow emission matrixes are also synthesized for analysis and comparison. To employ the outstanding characteristics of the compound of pure phosphorescent CDs and afterglow matrix, advanced information encryption/decryption and rapid fingerprint detection applications are designed. This EnT medicated enhancing RTP strategy provides a new design route to construct the CD-based material with long phosphorescence emission and high emission intensity.