Thermally Enhanced Phosphorescent Carbon Nanodots for Monitoring Cold‐Chain Logistics

Abstract

Room‐temperature phosphorescent materials, renowned for their long luminescence lifetimes, have garnered significant attention in the field of optical materials. However, the challenges posed by thermally induced quenching have significantly hindered the advancement of luminescence efficiency and stability. In this study, thermally enhanced phosphorescent carbon nanodots (CND) are developed by incorporating them into fiber matrices. Remarkably, the phosphorescence lifetime of the thermally enhanced CND exhibits a twofold enhancement, increasing from 326 to 753 ms, while the phosphorescence intensity experienced a tenfold enhancement, increasing from 25 to 245 as the temperature increased to 373 K. Rigid fiber matrices can effectively suppress the non‐radiative transition rate of triplet excitons, while high temperatures can desorb oxygen adsorbed on the surface of the CND, disrupting the interaction between the CND and oxygen. Consequently, a thermally enhanced phosphorescence is obtained. In addition, benefiting from the thermally enhanced phosphorescence property of CND, a warning indicator with an anti‐counterfeiting function for monitoring cold‐chain logistics is demonstrated based on CND.

Time Division Colorful Multiplexing Based on Carbon Nanodots with Modifiable Colors and Lifetimes

“…In recent years, phosphorescent carbon nanodots (CND) have attracted widespread attention due to their environmental friendliness, low cost, and excellent properties. − They have been widely applied in light-emitting diodes, − cell imaging, − information encryption − and biosensing fields. ,,, Given the excellent optical properties and environmental friendliness of CND, , they are ideal materials for optical multiplexing. In our previous work, we have demonstrated a time-division duplexing based on lifetime-engineering CND, and spatiotemporal overlapping information is thus resolved .…”