Photoluminescence-Tunable Carbon Nanodots: Surface-State Energy-Gap Tuning

The photoluminescence of carbon nanodots (C‐dots) can be tuned by changing their surface chemistry or size because the photoluminescence is a function of the surface‐state electronic transitions. Increasing the degree of surface oxidation leads to a narrowing of the energy gap of the surface; meanwhile, larger C‐dots with an extensive π‐electron system, which can couple with surface electronic states, can also lead to a narrowing of the energy gap of the surface states.