Multicolor carbon dot (CD)‐based nanomaterials offer a variety of opportunities for potential applications in bioimaging, optoelectronic devices, and information security. However, it still remains a challenge to modulate the conjugated π‐structure of CDs to achieve multicolor room‐temperature phosphorescence (RTP). Herein, the authors present a strategy based on thermally driven amorphous−crystalline phase transition to achieve multicolor carbonized polymer dots (CPDs) with the emission color tunable from green to orange‐red. This is the first report on multicolor RTP emission from CDs by means of thermal stimulus. Further investigations reveal that the formation of self‐protective covalently crosslinked frameworks and codoping of multiple heteroatoms play a crucial role in the production of RTP. RTP color tunability can be attributed to different crystalline contents of the conjugated π‐domain within CPDs. Potential application of the developed CPDs as printable and writable security inks for advanced multilevel anti‐counterfeiting and encryption is demonstrated. This work paves a path for the development of multicolor RTP materials and suggests great potential of CDs in exploiting novel optical materials toward intriguing applications.
Room-temperature phosphorescent (RTP) carbon dots offer unique opportunities in information security applications, but the delay time of such materials reported thus far is typically shorter than 10 s and thus...
Photoluminescence properties of silicate and borosilicate glasses codoped with Tb3+ and Sm3+ ions have been characterized by excitation and emission spectroscopies. When excited by ultraviolet light the glasses emit a combination of green and orange-red wavelengths giving white light. The ratio of the intensities of orange-red to green emissions can be tuned by varying both the concentration of the Sm3+ ion and an the composition of the glass matrix. The excitation and emission spectra show a self-quenching effect for the Sm3+ ions and an energy transfer from Tb3+ (D45) to Sm3+ (G5∕24).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.