Figure 1.

(a) Optical absorption (black) and photoluminescence (PL) emission excited at 530 nm (red) of ethanol-dispersed carbon dots (CDs). (b) $\mathsf{\mu }$-Raman/PL spectra of CDs deposited on ${\mathrm{SiO}}_2$/$\mathrm{Si}$ substrate (red) and bare substrate (black). Raman bands of silicon are highlighted by arrows.