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White Light Afterglow in Carbon Dots Achieved via Synergy between the Room-Temperature Phosphorescence and the Delayed Fluorescence.

Jinyang ZhuJunhua HuQiang HuXiaoyu ZhangElena V UshakovaKaikai LiuShixun WangXu ChenChongxin ShanAndrey L RogachXue Bai
Published in: Small (Weinheim an der Bergstrasse, Germany) (2021)
Carbon dot (CD) based long-lived afterglow emission materials have attracted attention in recent years, but demonstration of white-light room-temperature afterglow remains challenging, due to the difficulty of simultaneous generation of multiple long-lived excited states with distinct chromatic emission. In this work, a white-light room-temperature long-lived afterglow emission from a CD powder with a high efficiency of 5.8% and Commission International de l'Eclairage (CIE) coordinates of (0.396, 0.409) is realized. The afterglow of the CDs originates from a synergy between the phosphorescence of the carbon core and the delayed fluorescence associated with the surface CN moieties, which is accomplished by matching the singlet state of the surface groups of the CDs with the long-lived triplet state of the carbon core, resulting in an efficient energy transfer. It is demonstrated how the long-lived afterglow emission of CDs can be utilized for fabrication of white light emitting devices and in anticounterfeiting applications.
Keyphrases
  • room temperature
  • energy transfer
  • quantum dots
  • ionic liquid
  • high efficiency
  • light emitting
  • solid state
  • nk cells