News Article
Nanotechnology
GE Global Research Centre scientists have developed a carbon nanotube p-n junction diode based on electrostatic doping (Applied Physics Letters).
GE Global Research Centre scientists have developed a carbon nanotube p-n junction diode based on electrostatic doping (Applied Physics Letters). The single-wall tube is put between source-drain contacts on a silicon substrate. Underneath the tube in a silicon dioxide layer are two gates.
These provide electrostatic fields that create different doping conditions (charge carriers) in different parts of the tube.
The researchers report forward conduction and reverse blocking characteristics - in other words diode rectification behaviour. For low bias conditions, the characteristics follow closely the ideal diode equation with an ideality factor close to one.
The minimum separation of the split gates (0.5microns) is limited by the labs' optical lithography capability. The tubes are grown by a catalytic chemical vapour deposition (CVD) technique. Tube diameters range from 0.5-3.0nm.
