BARC/PUB/2017/1034

 
 

Graphene Quantum Dot Solid Sheets: Strong blue-light-emitting & photocurrent-producing band-gap-opened nanostructures

 
     
 
Author(s)

Bharathi, G.; Nataraj, D.; Premkumar, S.; Patra, N.; Jha, S. N.; Bhattacharyya, D.; and others
(A&MPD)

Source

Scientific Reports, 2017. Vol. 7 (1): pp. 1-17: Article no. 10850

ABSTRACT

Graphene has been studied intensively in opto-electronics, and its transport properties are well established. However, efforts to induce intrinsic optical properties are still in progress. Herein, we report the production of micron-sized sheets by interconnecting graphene quantum dots (GQDs), which are termed ‘GQD solid sheets’, with intrinsic absorption and emission properties. Since a GQD solid sheet is an interconnected QD system, it possesses the optical properties of GQDs. Metal atoms that interconnect the GQDs in the bottom-up hydrothermal growth process, induce the semiconducting behaviour in the GQD solid sheets. X-ray absorption measurements and quantum chemical calculations provide clear evidence for the metal-mediated growth process. The as-grown graphene quantum dot solids undergo a Forster Resonance Energy Transfer (FRET) interaction with GQDs to exhibit an unconventional 36% photoluminescence (PL) quantum yield in the blue region at 440 nm. A highmagnitude photocurrent was also induced in graphene quantum dot solid sheets by the energy transfer process.

 
 
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