Confinement-modulated junctionless nanowire transistors for logic circuits.

We report the controlled formation of nanoscale constrictions in junctionless nanowire field-effect transistors that efficiently modulate the flow of the current in the nanowire. The constrictions act as potential barriers and the height of the barriers can be selectively tuned by gates, making the device concept compatible with the crossbar geometry in order to create logic circuits. The functionality of the architecture and the reliability of the fabrication process are demonstrated by designing decoder devices.

Flexible gigahertz transistors derived from solution-based single-layer graphene.

Flexible electronics mostly relies on organic semiconductors but the limited carrier velocity in polymers and molecular films prevents their use at frequencies above a few megahertz. Conversely, the high potential of graphene for high-frequency electronics on rigid substrates was recently demonstrated. We conducted the first study of solution-based graphene transistors at gigahertz frequencies, and we show that solution-based single-layer graphene ideally combines the required properties to achieve high speed flexible electronics on plastic substrates. Our graphene flexible transistors have current gain cutoff frequencies of 2.2 GHz and power gain cutoff frequencies of 550 MHz. Radio frequency measurements directly performed on bent samples show remarkable mechanical stability of these devices and demonstrate the advantages of solution-based graphene field-effect transistors over other types of flexible transistors based on organic materials.