The United States developed super high flux led

The United States developed super high flux ledThe United States IBM and Duke University researchers recently succeeded in single wall carbon nanotubes ( single-walled carbon nanotube ), a high brightness light. They let the nano carbon tube part hanging in the silica substrate, led high bay  and the single carrier operations ( unipolar operation ), super high flux led, which results in carbon nanotubes suspended and supported to form the connecting surface of a high brightness light.

Researchers in the chemical vapor deposition ( chemical vapour deposition ), the diameter of 2to 3nm nano carbon tube horizontally on the fluted structure ( trench ) silica substrate, super high flux led, so that the carbon tube part across the top groove, adding palladium ( palladium ) as the source and drain, in the single carrier transmission conditions (i.e., the gate voltage of less than about3.1 volts and can cause the hole transmission, the gate voltage is greater than – 2.1 volts would trigger electronic transmission ), super high flux led, carbon nanotubes are substrate supporting and hanging part formed by the junction of emits infrared light, the luminous efficiency in the3 A current about every square nano107 a second photon, is a large area of LED105 times higher.

Researchers believe that the nano carbon tube light-emitting reason, lies in the nano carbon tube is supported and suspended part of the ground near the surface, energy band bending, the electric field can accelerate the carrier, and then generate excitons ( exciton, namely bound pairs of electrons and holes ); when the electron-hole pairs when combined with will shine. super high flux led. The researchers calculated, the excitation efficiency is respectively from two ends of electron and hole injection combined with efficiency more than 1000 times.

This study proves that in the low dimensional nanostructures, electron and hole has the very strong attraction,  super high flux led, carrier and atomic vibration coupling is weak, it also demonstrated for the first time in one-dimensional systems, molecular heat carrier ( high energy carrier ) impact excitation ( impact excitation ) phenomenon.

Since carbon nanotubes is issued by the1-2/ M wavelength of infrared light, so it has application in the optical communication potential, at the same time, the emission wavelength can be tuned by changing the diameter of carbon tube to be adjusted. In addition, super high flux led, the future of these carbon nanotubes luminous body can also be associated with the same carbon tube or silicon electronic components integrated on the same chip, to become the new electronic or optoelectronic components.