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Title: Red shift in the photoluminescence of colloidal carbon quantum dots induced by photon reabsorption

We synthesize the colloidal carbon/graphene quantum dots 1–9 nm in diameter and study their photoluminescence properties. Surprisingly, the luminescence properties of a fixed collection of colloidal carbon quantum dots can be systematically changed as the concentration varies. A model based on photon reabsorption is proposed which explains well the experiment. Infrared spectral study indicates that the surfaces of the carbon quantum dots are substantially terminated by oxygen atoms, which causes their ultra-high hydrophilicity. Our result clarifies the mystery of distinct emission colors in carbon quantum dots and indicates that photon reabsorption can strongly affect the luminescence properties of colloidal nanocrystals.
Authors:
; ; ; ;  [1]
  1. Department of Physics, Southeast University, Nanjing 211189 (China)
Publication Date:
OSTI Identifier:
22283066
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 9; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 77 NANOSCIENCE AND NANOTECHNOLOGY; COLLOIDS; COLOR; CONCENTRATION RATIO; GRAPHENE; OXYGEN; PHOTOLUMINESCENCE; PHOTONS; QUANTUM DOTS; RED SHIFT; SURFACES