YORKTOWN HEIGHTS, N.Y. IBM Research's said Thursday (May 1) its carbon nanotube technology has enabled the world's smallest solid-state emitter and the first electrically-controlled single-molecule light emitter. The light-emitting nanotube (LEN) operates in the important 1.5-micron range, portending optical communications on silicon chips with integrated 1.4-nm diameter LENs.
"Our results show that nanotube-based light emitters can potentially be integrated with silicon electronic components, opening up new possibilities in electronics and optoelectronics," said Phaedon Avouris, manager of nanoscale science, IBM Research.
While emphasizing that these are research results, IBM showed a detailed mathematical proof along with verifying laboratory
demonstrations of hitherto speculated properties of light emission by carbon nanotubes.
In a nutshell, IBM discovered that simultaneous injection of electrons into one end, and holes into the other end, of a
carbon nanotube causes it to emit light at the 1.5 micron wavelength.
"We have advanced our understanding of the electrical properties of nanotubes to emit light, thereby accelerating the development of electronic and optical applications" said Avouris.
Unlike light-emitting diodes, which emit light whenever a voltage appears across their two-terminals, the three-terminal LEN device uses the nanotube as the channel of a transistor, allowing the electrons and holes to be poised to flow into the source and drain, with the third terminal, the gate, turning the current on and off.
Avouris previously used carbon nanotubes for the world's best transistor as well as for IBM's bulk process by which they manufacture nanotubes.
Arrays of LENs, according Avouris, will not only convert electricity into light, but because they are transistors, can be used to process informationlike storing the pixel values for a nanoscale display. IBM also released a detailed characterization of the LENs' light emitting propertiescalling the nanotube-based material "uniquely one dimensional."
Nanotubes can be microns long, but are only 1.4 nanometer in diameter, inviting the mathematical approximation of one-dimensionality.