Facile synthesis and photoluminescence mechanism of graphene quantum dots

Journal Article · Sun Dec 28 04:00:00 EST 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4904958· OSTI ID:22399173

Yang, Ping; Zhou, Ligang; Zhang, Shenli; Pan, Wei; Shen, Wenzhong ^[1]; Wan, Neng ^[2]

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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)

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.

• OSTI ID: 22399173
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 24 Vol. 116; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

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