The electronic origins of fluorescence in carbon nanotubes
(PHYSorg.com Nanotechnology)

Technological progress is often driven by materials science. High-tech devices require `smart` materials that combine a range of properties. An impressive current example is carbon nanotubes (CNTs)-single sheets of carbon atoms rolled into a cylinder. These ultrathin tubes have enormous mechanical strength and electrical conductivity. They also emit infrared fluorescent light, rendering them detectable. This makes them exciting materials for future bio-imaging technology, but the mechanism has proven surprisingly elusive.