Tuning the properties of graphene quantum dots by passivation

Abstract

The electronic and optical properties of graphene quantum dots (GQDs) of size less than 10 nm are different from those of graphene sheets due to quantum confinement effects. For analyzing...

Engineering functionalization and properties of graphene quantum dots (GQDs) with controllable synthesis for energy and display applications

“…116 In other recent research, calculations showed that S and B doping can enhance the QY in the NIR region by 26% and 29%, respectively. 103,117 Meanwhile, the mechanism behind GQDs' photoluminescence is not yet fully understood because of their complex electronic band structure, which involves non-radiative transitions. The non-radiative transitions lead to recombination, making the understanding of the PL mechanism challenging.…”

“…161,243 Furthermore, many studies employing DFT calculations model GQDs as monolayer and small-sized structures for the sake of computational convenience when explaining the structure and band gap of GQDs. 244,245 Therefore, the issue of self-assembly of GQDs cannot be ignored, and it is essential to consider methods to mitigate aggregations of GQDs. Two primary strategies are available for this purpose, as follows.…”

“…The optical and electronic properties of GQDs can be influenced not only by the presence or absence of functional groups and dopants but also by their introduction locations and quantities. 103,244 Additionally, the edge structures such as zigzag and armchair, as well as physical defects, are known to impact the characteristics of GQDs. [67][68][69] There are numerous theoretical studies on this topic, and research on controllable synthesis has been conducted.…”

Comprehensive advances in the synthesis, fluorescence mechanism and multifunctional applications of red-emitting carbon nanomaterials

“…The uorine has the highest effect among heavy atoms due to the electronwithdrawing capacity of uorine, decreases the energy gap between the HOMO and LUMO, and leads to the shiing of excitation and emission wavelengths towards the red region. [75][76][77][78][79][80] Li et al developed tetraphenyl porphyrin-derived red-emitting carbon dots via a simple solvothermal method using a sulfonation reaction with sulfuric acid. The developed carbon dots were utilized for the bioimaging of HeLa cells.…”

Enhanced NIR fluorescence quantum yield of graphene quantum dots using dopants

“…One of the new challengers in the carbon family is the graphene quantum dot (GQD), which has a very large bohr excitonic radius and is dependent on the dielectric properties of its surroundings [12,13]. GQDs typically have fascinating properties originating from two-dimensional (2D) graphene along with extraordinary physical and chemical properties of QDs such as quantum confinement effects, desirable band gap depending on size and shape and [14][15][16][17], indicating that they have many possible uses in the optical, electrical, and medicinal sectors.…”