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Title: Facile synthesis and photoluminescence mechanism of graphene quantum dots

We report a facile hydrothermal synthesis of intrinsic fluorescent graphene quantum dots (GQDs) with two-dimensional morphology. This synthesis uses glucose, concentrate sulfuric acid, and deionized water as reagents. Concentrated sulfuric acid is found to play a key role in controlling the transformation of as-prepared hydrothermal products from amorphous carbon nanodots to well-crystallized GQDs. These GQDs show typical absorption characteristic for graphene, and have nearly excitation-independent ultraviolet and blue intrinsic emissions. Temperature-dependent PL measurements have demonstrated strong electron-electron scattering and electron-phonon interactions, suggesting a similar temperature behavior of GQDs to inorganic semiconductor quantum dots. According to optical studies, the ultraviolet emission is found to originate from the recombination of electron-hole pairs localized in the C=C bonds, while the blue emission is from the electron transition of sp{sup 2} domains.
Authors:
; ; ; ;  [1] ;  [2]
  1. Laboratory of Condensed Matter Spectroscopy and Opto-Electronic Physics, and Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China)
  2. SEU-FEI Nano Pico Center, Key Laboratory of MEMS of Ministry of Education, School of Electronics Science and Engineering, Southeast University, Nanjing 210096 (China)
Publication Date:
OSTI Identifier:
22399173
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 24; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ABSORPTION; ELECTRON-PHONON COUPLING; ELECTRONS; EXCITATION; FLUORESCENCE; GLUCOSE; GRAPHENE; HOLES; HYDROTHERMAL SYNTHESIS; MORPHOLOGY; PHASE TRANSFORMATIONS; PHOTOLUMINESCENCE; QUANTUM DOTS; RECOMBINATION; SEMICONDUCTOR MATERIALS; SULFURIC ACID; TEMPERATURE DEPENDENCE; TWO-DIMENSIONAL SYSTEMS; ULTRAVIOLET RADIATION; WATER