Publications by authors named "Sellan Premkumar"

Nonclassical crystallization represents an innovative pathway that utilizes nanoparticles, enabling the generation of single crystals, going beyond a classical mechanism dependent on atoms, ions, or molecules. Our investigation has revealed hierarchical structures emerging via the aggregation and fusion of primary silicon quantum dots (SiQDs). In contrast to the classical ion-by-ion crystallization process, the primary SiQDs initially undergo aggregation, followed by fusion and their subsequent crystallization, leading to the ultrafast crystal growth of sodium hexafluorosilicate (SHFS) microrods with diverse morphologies.

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Article Synopsis
  • Blue emission from Oleylamine-Acetone clusters forms at room temperature through aging-induced hydrogen bonding, producing flower-like aggregates that emit red light due to exciton delocalization.
  • The aging process leads to imine bond formation between Oleylamine and Acetone, and the paper details the experimental setup and mechanisms behind these molecular interactions.
  • The research also applies this aging method to InS quantum dot systems, demonstrating improved charge transport in photoconductive devices by detaching Oleylamine from the QD surface, ultimately achieving high photocurrent values.
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Graphene-nanostructured systems, such as graphene quantum dots (GQDs), are well known for their interesting light-emitting characteristics and are being applied to a variety of luminescence-based applications. The emission properties of GQDs are complex. Therefore, understanding the science of the photophysics of coupled quantum systems (like quantum clusters) is still challenging.

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Detection of visible blind UV radiation is not only interesting but also of technologically important. Herein, we demonstrate the efficient detection of UV radiation by using cluster like ZnS quantum dot solid nanostructures prepared by simple reflux condensation technique. The short-chain ligand 3-mercaptopropionic acid (MPA) involved in the synthesis lead to the cluster like formation of ZnS quantum dots into solids upon prolonged synthesis conditions.

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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.

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