Transfer-Free P-Type Graphene Field-Effect Transistors with High Mobility and On/Off Ratio

Abstract

Graphene is considered a promising material because of the novel functionalities associated with its outstanding charge transport properties. However, because graphene has no bandgap, its electrical conductivity cannot be controlled as in semiconductors, at present. Although many attempts have been made to achieve a bandgap opening in graphene, a meaningful bandgap opening for p-type field-effect-transistors (FETs) still remains a challenge. In this study, boron-doping in transfer-free monolayer graphene was successfully demonstrated for digital logic devices. Our approach is highly versatile, as it allows the fabrication of p-type graphene FETs having a mobility of ~290 cm2V-1s-1, an on/off ratio of 1.9 × 105, and a subthreshold swing of 0.58 Vdec-1. The scalability and versatility of this transfer-free approach for the fabrication of p-type graphene FETs pave the way for high-performance p-type graphene-based digital logic circuits.

Keywords: Transfer-free graphene, Large domain size, Boron-doped graphene, p-type graphene-FETs, Digital logic devices, Facing-target-sputtering