Carbon dots photoluminescence

Sun YP et al (2006) Quantum-sized carbon dots for bright and colorful photoluminescence. J Am Chem Soc 128 7756-7757... 

Carbon dots. Carbon dots (C-dots) refer to small carbon nanoparticles endowed with a bright photoluminescence, similar to the one described for quantum dots (see below). However C-dots do not contain heavy-metal atoms with potential health and environmental hazards. Therefore they have been proposed, along with silicon nanoparticles (see below) as potential alternatives to quantum dots for bioimaging. ° ... 

Similarly to other semiconducting materials, the photoluminescence of C-dots relies on radiative recombination of confined electrons and holes generated previously by efficient photoinduced charge separation processes. In addition, this emission is efficiently quenched by electron donor or acceptor molecules in solution, indicating that photo-excited carbon dots are both excellent electron donors and electron acceptors. ... 

Keywords Silicon, germanium, carbon, alloys, nanostructures, optoelectronics, light emission, photoluminescence, electroluminescence, quantum well, quantum wire, quantum dot, superlattices, quantum confinement. 

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