Comparative photoluminescence study of nitrogen-doped carbon dots co-doped with boron and sulphur.

Although different studies in carbon dots (CDs) have been reported based on heteroatom doping, most of them have focussed on the enhancement of fluorescence properties. Here we report a comparative study of both fluorescence and room-temperature phosphorescence (RTP) of nitrogen-sulphur-doped CDs (N-S CDs) and nitrogen-boron-doped CDs (N-B CDs) with N-doped CDs (N CDs). The CDs used in the study were synthesized through microwave-assisted pyrolysis.

Cool white, persistent room-temperature phosphorescence in carbon dots embedded in a silica gel matrix.

Herein we report the observation of room-temperature phosphorescence from carbon dots (CDs) embedded in a silica gel matrix. The precursors used in the synthesis (malonic acid and ethylene diamine) were chosen to have the surface of the CDs rich in C[double bond, length as m-dash]O and C[double bond, length as m-dash]N functionalities. The CDs in an aqueous dispersion exhibit an intense blue fluorescence and upon incorporation into silica gel demonstrate a green after-glow, which is visible even to the naked eye.

White-Light-Emitting Carbon Dots Prepared by the Electrochemical Exfoliation of Graphite.

The single-step synthesis of white-light-emitting carbon dots (CDs) through a green, facile and cheap electrochemical route by using graphite rods as the carbon source is reported. Under UV excitation, the aqueous dispersion of as-synthesised CDs exhibit broad-band emission, which covers a significant fraction of the visible spectrum, owing to the heterogeneity in particle size and surface functional groups. The CDs were further explored for their potential as UV-to-visible colour convertors under remote-phosphor technology by capping a λ=365 nm UV light-emitting diode (LED) chip with CD-loaded poly(methyl methacrylate) to obtain the following colour parameters: Commission Internationale de l'Eclairage chromaticity coordinates (0.