Graphene-based Field Effect Diode

Abstract

One of the major problems with Graphene transistors is the small On/Off current ratio. In spite of introducing various methods to improve this problem, like patterning the Graphene layer or using the Graphene nanoribbons, this issue still limits the use of Graphene transistors. Here, we present a new Graphene-based, 4-terminal device and discuss its application as a Graphene-based transistors. The proposed structure is a Filed Effect Diode (FED) in which Graphene acts as the channel. In the structure of Graphene-Field Effect Diode (G-FED), two gates are located over the channel and biased oppositively to electrically induce n or p regions in Graphene layer. As the Off current of G-FED is limited to only the leakage current of a reverse-biased diode, the On/Off current ratio is large in comparison with the comparable Graphene Filed effect Transistor (G-FET). We have measured the current-voltage curves of G-FED as well as the carrier concentration and energy band diagram in both On and Off states. It has been observed that G-FED performance is similar to a silicon-based FED with rectifying characteristics. We have demonstrated that the On/Off current ratio obtained for the G-FED is about 100 while this value is less than 15 for the G-FET with the same dimensions. Additionally, the G-FED has the same fabrication process as the G-FET and no difficulty is needed for patterning the Graphene layer to get the high On/Off current ratio. This demonstration reveals the great potential of Graphene-based Field Effect Diode in digital nanoelectronics applications as well as analog mixers.