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Evidence for Edge‐State Photoluminescence in Graphene Quantum Dots
Author(s) -
Lingam Kiran,
Podila Ramakrishna,
Qian Haijun,
Serkiz Steven,
Rao Apparao M.
Publication year - 2013
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201203441
Subject(s) - graphene , materials science , quantum dot , photoluminescence , graphene nanoribbons , passivation , nanotechnology , chemical vapor deposition , carbon nanotube , annealing (glass) , fabrication , optoelectronics , layer (electronics) , composite material , medicine , alternative medicine , pathology
For a practical realization of graphene‐based logic devices, the opening of a band gap in graphene is crucial and has proven challenging. To this end, several synthesis techniques, including unzipping of carbon nanotubes, chemical vapor deposition, and other bottom‐up fabrication techniques have been pursued for the bulk production of graphene nanoribbons (GNRs) and graphene quantum dots (GQDs). However, only limited progress has been made towards a fundamental understanding of the origin of strong photoluminescence (PL) in GQDs. Here, it is experimentally shown that the PL is independent of the functionalization scheme of the GQDs. Following a series of annealing experiments designed to passivate the free edges, the PL in GQDs originates from edge‐states, and an edge‐passivation subsequent to synthesis quenches the PL. The results of PL studies of GNRs and carbon nano‐onions are shown to be consistent with PL being generated at the edge sites of GQDs.