Graphene quantum dot

Graphene quantum dots (GQDs) represent single-layer to tens of layers of graphene of a size less than 30 nm. Due to its exceptional properties such as low toxicity, stable photoluminescence, chemical stability and pronounced quantum confinement effect, GQDs are considered as a novel material for biological, opto-electronics, energy and environmental applications. Graphene quantum dots (GQDs) represent single-layer to tens of layers of graphene of a size less than 30 nm. Due to its exceptional properties such as low toxicity, stable photoluminescence, chemical stability and pronounced quantum confinement effect, GQDs are considered as a novel material for biological, opto-electronics, energy and environmental applications. The graphene quantum dot (GQD) is becoming an advanced multifunctional material for its unique optical, electronic, spin, and photoelectric properties induced by the quantum confinement effect and edge effect. GQDs are fragments limited in size, or domains, of a single-layer two-dimensional graphene crystal. Spectral studies have found that in almost all cases, GQDs are not single-layer graphene domains, but multi-layer formations containing up to 10 layers of reduced graphene oxide (rGO) from 10 to 60 nm in size. Presently, several techniques have been developed to prepare GQDs; these techniques mainly include electron beam lithography, chemical synthesis, electrochemical preparation, graphene oxide (GO) reduction, C60 catalytic transformation, the microwave assisted hydrothermal method (MAH), the Soft-Template method, the hydrothermal method, and the ultrasonic exfoliation method. GQDs have various important applications in bioimaging, cancer therapeutics, temperature sensing, drug delivery, surfactants, LEDs lighter converters, photodetectors, OPV solar cells, and photoluminescent material, biosensors fabrication.