Visible photoluminescence from ruthenium-doped multiwall carbon nanotubes

Visible photoluminescence at 515 nm of ruthenium-doped multiwall carbon nan otubes, fabricated on quartz substrates using a chemical vapor deposition t echnique, is reported. The well-aligned nanotubes serve as templates for th e luminescent, residual ruthenium-iron catalyst particles contained within the nanotubes, restricting the particle size to about 10 nm. The synthesis technique can be readily extended to other luminescent dopants; moreover, s ince nanotube arrays can be readily grown from patterned substrates, nanotu be-based optoelectronic devices may be achieved. (C) 2001 American Institut e of Physics.