PSE Success Story:
Electrolyte-gated Carbon Nanotube
Carbon nanotubes are robust nanostructures with unique optical and electronic properties that
could lead to innovations in nanoscale circuits and telecommunication applications.
|Aligned, single-walled carbon nanotubes placed in an
FET device enables the control of the recombination
point of electrons and holes in the nanotubes and the
resulting control of light emission from the structure.
The electroluminescence image from individual
SWNTs integrated over gate voltage is shown above.
|Electrolyte gating of the FET device enables control over the light emission point at very low applied voltages.
Carbon nanotubes enable the efficient transport
of both electrons and holes, which recombine
in the nanotubes to produce near-infrared
light emission within the telecommunication
window. Controlled emission can be realized
with nanotubes in a field-effect transistor (FET)
structure that allows for injection of both charge
carriers. The challenge is to control the charge
transport and light emission by applying low
voltages, while achieving high brightness at the
With the state-of-the-art optical
microscopy and spectroscopy capabilities
of Argonne’s Center for Nanoscale
Materials, a team of researchers
developed FET devices with highly
aligned, dense arrays of carbon
nanotubes grown by chemical vapor
deposition on quartz as the active/emissive
layers. By employing electrolyte gating
instead of a traditional oxide dielectric, the
team was able to control charge transport
at extremely low voltages.
The scientists observed near-infrared light
emission from many carbon nanotubes at
the same time, and were able to control
the position of the emission zone along
individual nanotubes by changing the
applied voltages. The scientists were able
to control the position of the emission zone along individual nanotubes by changing the applied
voltages. These nanoscale light sources could one day find applications in telecommunication
devices, but improvements in efficiency are still needed.
“Light emitting devices based on large-scale arrays of carbon nanotubes may represent
an important first step toward realistic applications in optoelectronics,” said John Rogers,
a professor at University of Illinois at Urbana-Champaign, who worked with Argonne
researchers on the project.
- Electroluminescence from Electrolyte-gated Carbon Nanotube Field-effect Transistors (593 kB pdf)