Fluorescence “Giant” Red Edge Effect
1.4 Conclusions and future aspect
The PL property of the carbon dots is undoubtedly the most intriguing yet the most intangible characteristic of these nanosystems. Even after 15 years of rigorous and exponentially growing research on carbon dots, the problem of understanding their fundamental photophysics is still open. This difficulty particularly arises from the large variability in carbon dot structures. The strong luminescence behavior is asso- ciated with excellent tunability and sensitivity toward the local environment, i.e., solvents, ions, pH. Another notable aspect is their coverage of the broad spectral Figure 1.26 Illustration of the structures of the CQD-LED and doped CQD-LEDs[34].
CQDs, Carbon quantum dots;LED, light-emitting diodes.
Source: Reprinted with permission. Copyright 2018 Royal Society of Chemistry.
range from ultraviolet to visible. This is responsible for the multicolor luminescence in the visible range even though both the absorption and emission efficiencies fade out at longer wavelengths. Luminescence is also characterized by high quantum yields, which, primarily rely on synthetic conditions and procedures. However, as evident by the recent research works, the carbon dots are undoubtedly one of the most versatile nanomaterials in terms of their properties and diverse range of appli- cations that include but are not limited to biomolecule sensing, metal ion sensing, drug delivery, and optoelectronic devices. Apart from providing such a wide range of applications, the unique carbon dot photophysics egg us to explore the heterogeneity-driven optical behavior of a material. It remains unpredictable how a given carbon dot structure will come up with specific photophysical behavior. We believe this decade would get enriched with many more significant explorations that would better our understanding of this wonderful nanomaterial.
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The physical and chemical properties of carbon dots via computational modeling
Arup Chakraborty
Department of Chemistry, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel