Using a chemical vapor-deposition technique, a research team from Pennsylvania State University in University Park and the Center for Applied Energy Research in Lexington, Ky., has fabricated ruthenium-doped multiwall carbon nanotubes that photoluminesce at 515 nm.

The researchers predict that the method, reported in the Dec. 10 issue of Applied Physics Letters, may be applied to other transition-metal and rare-earth elements to produce different frequencies of luminescence, potentially leading to display applications with pixel sizes down to 10 nm. The team is considering pursuing such applications commercially.