Login / Signup

Symmetry-Triggered Tunable Phosphorescence Lifetime of Graphene Quantum Dots in a Solid State.

Yongqiang LiLiangfeng ChenSiwei YangGenwang WeiXue RenAnli XuHang WangPeng HeHui DongGang WangCaichao YeGuqiao Ding
Published in: Advanced materials (Deerfield Beach, Fla.) (2024)
Studying the phosphorescent mechanisms of carbon nanostructures synthesized by the "bottom-up" approach is key to understanding the structure modulation and the interfacial properties of carbon nanostructures. In this work, the relationships among symmetry of precursors in the "bottom-up" synthesis, structures of products, and phosphorescence lifetimes of graphene quantum dots (GQDs) were studied. The symmetry matching of precursors in the formation of a D 6h graphene-like framework was considered the key factor in controlling the separability of sp 2 domains in GQDs. As the separability of sp 2 domains in GQDs increased, the phosphorescence lifetimes (14.8-125.5 ms) of GQDs in the solid state could be tuned. Machine learning was used to define the degree of disorder (S) of the GQD structure, which quantitatively describes the different space groups of precursors. The negative correlation between S and the oscillator strength of GQDs was uncovered. Therefore, S could be recognized as reflective of oscillator strength in the GQD structure. Finally, based on the correlations found between the structures and phosphorescence lifetimes of GQDs, GQDs with an ultralong phosphorescence lifetime (28.5 s) were obtained. Moreover, GQDs with visible phosphorescence emission (435-618 nm) were synthesized. This article is protected by copyright. All rights reserved.
Keyphrases
  • room temperature
  • solid state
  • quantum dots
  • ionic liquid
  • machine learning
  • high resolution
  • multiple sclerosis
  • mass spectrometry
  • artificial intelligence