RTPs Join the Dots for Enhanced Authentication

A research team at the Hefei Institutes of Physical Science, China has devised an innovative method to prepare carbonised polymer nanodots capable of emitting multicolour ultralong room-temperature phosphorescence (RTP) ranging from blue to green. These materials demonstrate significant potential applications in anticounterfeiting and information encryption.

Schematic for the preparation and application of dual-color phosphorescence oP-CDs@B2O3 RTP materials.

RTP materials have emerged as crucial components in anticounterfeiting technologies due to their unique ability to emit light for extended periods after the excitation source is removed. This prolonged glow is difficult to replicate with standard materials, making RTP an effective tool for distinguishing authentic products from counterfeits. RTP materials are used in various security features such as invisible ink for printing, security labels, and embedded markers in currency, identification documents, and branded goods.

Among RTP materials, carbon dots (CDs) are notable for their ease of production, light stability, and safety. However, achieving bright and long-lasting RTP with CDs has been challenging due to the non-radiative loss of energy. Additionally, producing different phosphorescent colours from a single carbon dot material has been difficult, limiting their usability. Therefore, developing multicolour, long-lived, and high quantum yield RTP carbon dots represents a notable step forward.