Review—Aggregation-Induced Emission in Carbon Dots for Potential Applications

Abstract

Aggregation-induced emission (AIE) has unlocked a completely new research area corresponding to application potentials of luminescent materials. Notably, carbon dots (Cdots) are emerging as well-recognized alternative to organic dyes because of their fascinating fluorescence properties. They exhibit improved emission when aggregated due to the changes in solvent polarity, higher concentration, externally added chemical species. Herein, a review on the AIE property is demonstrated with a substantial emphasis on Cdot optical property. Mechanistic overview along with application potentials of the same in sensing, optoelectronic devices, fingerprints recognition and solar concentrators are highlighted. Finally, a summary corresponding to recent developments and future prospects have been discussed.

Aggregation-Induced Modulation of the Optoelectronic Properties of Carbon Dots and Removal of Cd2+ Ions with Sustainable Use in Photocurrent Generation

“…However, the aggregated carbon dots (in organic medium) show excellent current enhancement compared to the nonaggregated carbon dots. The conductivity of the carbon dots in aqueous medium (nonaggregated state) could be attributed to the presence of sp 2 C–C bonds, which allow the flow of electrons through the conjugations. , In the organic solvent, the carbon dots undergo aggregation and this leads to the π–π stacking interactions between the carbonized cores of the C-dots . Owing to this π–π stacking, the effective area of conjugation increases enormously in the aggregated C-dots.…”

“…38,58 In the organic solvent, the carbon dots undergo aggregation and this leads to the π−π stacking interactions between the carbonized cores of the C-dots. 59 Owing to this π−π stacking, the effective area of conjugation increases enormously in the aggregated C-dots. This makes the flow of electrons in the aggregated system much feasible compared to that in the nonaggregated state.…”

Effect of post-treatment drying processes on the optical and photothermal properties of carbon nanodots derived via microwave-assisted method

“…As demonstrated in Figure 3a, CNDs generally exhibit broad optical absorption in the ultraviolet (UV) region (200-350 nm). The absorption peaks appeared at around 230-280 nm are due to -* electronic transition of aromatic C=C in the core of CNDs [28] and another peak at 335 nm is owned to n-* transition of C=O/C-N/C=N bonds [29]. In addition, the visible absorption band (above 400 nm) is attributed to the amine groups on the CNDs surface [30] or surface defects that might occur during the synthesis.…”

“…One reason for this phenomenon should be the better absorption of CND-FD since more electrons transfer from HOMO to LUMO, then more possibilities to quench fluorescence and produce heat from lattice vibration or non-radiative relaxation of photoinduced electrons [36]. Moreover, some literatures demonstrated that aggregation might occur during oven drying process and induce radiative emission [28,37] that diminishes the possibility of producing heat through non-radiative relaxation. To further study the photothermal performance of CNDs in solar evaporation systems, water evaporation rate and evaporation efficiency were calculated using equation ( 1) dan (2).…”

Development of Highly Luminescent Water-Insoluble Carbon Dots by Using Calix[4]pyrrole as the Carbon Precursor and Their Potential Application in Organic Solar Cells

“… 1 − 5 , 9 − 11 Therefore, preparation of hydrophobic/amphiphilic CDs with high quantum yields to be used in photovoltaic applications, such as organic solar cells, has become an important challenge. 12 − 15 …”