Figure 4.
The high QY of CDs. (A) Electrons are excited from the ground state and trapped by the surface states and excited electrons return to the ground state. Adapted with permission from 76. Copyright 2013, John Wiley and Sons. (B) The QY of CDs was affected by the π-electron system and the O-H group. Adapted with permission from 88. Copyright 2018, American Chemical Society. (C) A synthetic strategy for highly QY CDs by hydrothermal treatment of ethanol in aqueous hydrogen peroxide (H2O2) solution. (D-F) TEM image, XRD pattern and Raman spectrum of the CDs, indicating high crystallinity of the CDs. Adapted with permission from 76. Copyright 2015, Elsevier.