The particle size-dependent photoluminescence of nanodiamonds

The intrinsic defects- and impurities-originated photoluminescence from nanodiamond particles of various sizes (5–500 nm) were observed. Luminescence spanning from 500 nm to 800 nm can be excited with 488 nm and 532 nm wavelengths lasers without any high-energy treatment to create the defects/impurities. The luminescence is found to be particle-size and laser-wavelength dependent, suggesting different kinds of defects/impurities predominantly sustain the luminescence from nanodiamonds of different sizes.