Researchers demo triple-mode graphene transistor

Researchers at Rice University and the University of California, Riverside have taken advantage of another quirk in graphene's arsenal, ambipolarity, to build and test a triple mode transistor, that could lead to yet smaller and cooler (not in the iPod sense) wireless devices.

Conventionally, ability of a transistor to conduct either electrons (negative charge) or holes (positive charge) is fixed during fabrication. But graphene is ambipolar – that is it can conduct either positive or negative charges (that'€™s p and n type, for those who like to know that sort of thing). Building on this property, Professors Kartik Mohanram and Alexander Balandin have designed a transistor that can switch between p and n modes on the fly. The third mode conducts both electrons and holes equally.

The flexibility of the transistor means that it can carry out a level of signal processing that would normally take several piece of silicon: it acts as an amplifier and can alter the phase and frequency of a signal. As such, it has tremendous potential to be useful in wireless communications, where phase and frequency changes are used to encode data.

According to Technology Review (where you can read more about the work), Mohanram said that the trick now will be to get circuit designers to start thinking about the possibilities of ambipolarity, and other properties of the emerging new nanomaterials.