Optically Active Defects Improve Carbon Nanotubes

The optical properties of carbon nanotubes, which consist of a rolled-up hexagonal lattice of sp2 carbon atoms, can be improved through defects. A new reaction pathway enables the selective creation of optically active sp3 defects. These can emit single photons in the near-infrared even at room temperature. Simon Settele (Heidelberg) - The properties of carbon-based nanomaterials can be altered and engineered through the deliberate introduction of certain structural "imperfections" or defects. The challenge, however, is to control the number and type of these defects. In the case of carbon nanotubes - microscopically small tubular compounds that emit light in the near-infrared - chemists and materials scientists at Heidelberg University led by Jana Zaumseil have now demonstrated a new reaction pathway to enable such defect control. It results in specific optically active defects - so-called sp3 defects - which are more luminescent and can emit single photons, that is, particles of light.