Afterglow Carbon Dots: From Fundamentals to Applications

Abstract

The ability of carbon dots (CDs) to emit afterglow emission in addition to fluorescence in response to UV-to-visible excitation allows them to be a new class of luminescent materials. When compared with traditional organic or inorganic afterglow materials, CDs have a set of advantages, including small size, ease of synthesis, and absence of highly toxic metal ions. In addition, high dependence of their afterglow color output on temperature, excitation wavelength, and aggregation degrees adds remarkable flexibility in the creation of multimode luminescence of CDs without the need for changing their intrinsic attributes. These characteristics make CDs particularly attractive in the fields of sensing, anticounterfeiting, and data encryption. In this review, we first describe the general attributes of afterglow CDs and their fundamental afterglow mechanism. We then highlight recent strategic advances in the generation or activation of the afterglow luminescence of CDs. Considerable emphasis is placed on the summarization of their emergent afterglow properties in response to external stimulation. We further highlight the emerging applications of afterglow CDs on the basis of their unique optical features and present the key challenges needed to be addressed before the realization of their full practical utility.

Carbon dots from eco-friendly precursors for optical sensing application: an up-to-date review

“…Nazri and co-workers have reviewed the CDs for optical sensing applications based on colorimetry, optical fibres and surface plasmon resonance (Nazri et al 2021). Later Peng et al highlighted the emerging strategies in the fabrication of CDs with stimuli responsive afterglow luminescence and the key challenges to be overcome for their full real-life utility (Peng et al 2021). Li et al emphasized the unique electronic, fluorescent, photoluminescent, chemiluminescent and electrochemiluminescent properties of CDs for potential use in sensing applications .…”

Efficient blue TADF-type organic afterglow materialviaboric acid-assisted confinement

“…[1][2][3][4] As the emission lifetime of afterglow materials is longer than 0.1 s, their emission signals can be recorded by low-cost optical equipment. 2,[4][5][6][7] Even human naked eyes and phone cameras could record and distinguish the color, intensities, and durations of afterglow. This allows their wider applications for fabricating portable anticounterfeiting devices.…”

Preparation of Carbon Nanodots with Ultraviolet Emission by Pulsed Laser Ablation

“…Consequently, CNDs in other previous reports typically generated blue-to-green fluorescence. [3,[24][25][26]34] As the excitation wavelength increases from 300 to 500 nm, the emission peak red shifts from 400 to 600 nm accordingly and the emission intensity decreases in the long-wavelength range. UV emission can only be observed from the CNDs upon suppression of the defect state and radiative surface state.…”