Performance Estimation of Graphene Field-Effect Transistors Using Semiclassical Monte Carlo Simulation

Abstract

A semiclassical Monte Carlo simulation was run to estimate the performances of a monolayer and a bilayer (with vertical electric field of 1 V/nm applied) graphene-channel field-effect transistor (FET). The vertical field produces a band gap of 0.16 eV and gives semiconductive properties in the bilayer graphene. Electrons in monolayer graphene show a notable velocity overshoot of up to 7.6×107 cm/s. A sub-0.1 ps transit time is also expected in a 65-nm channel device. The performance of a bilayer graphene-channel FET is inferior to a monolayer graphene one, but comparable with that of an InP high electron mobility transistor (HEMT). This lower performance may be attributed to the electron effective mass produced by the vertical field.

Diffusive Thermoelectric Power in Highly Asymmetric Bilayer Graphene Nanoribbons

“…27 However, for an asymmetric BG with very narrow ribbon width, e.g., 1 nm to 5 nm, it is expected that a negative differential resistance will be exhibited, since the onedimensional electric current is directly proportional to the band gap via the density-of-states function, which can be modulated either by an external transverse and/or longitudinal electric field or by varying the level of carrier concentration. 28 This is not particularly featured in BG-based FETs, 29 since with the increase in asymmetry, near the k x = 0 region, a bulging of the lower conduction band occurs. This brings about an increase in the band gap instead of a decrease, and hence no carriers are populated in the lower subband.…”

Influence of Band-Gap Opening on Ballistic Electron Transport in Bilayer Graphene and Graphene Nanoribbon FETs

“…As mentioned above, the electronic states of A-GNRs and BLGs highly depend on geometrical configurations and operating conditions, and thus systematic investigation is needed to understand their relative advantages for use in FET channels. However, only spot data have been used to assess their upper-limit performances so far, especially for BLG-FETs [15], [16]. With recent progress in atomically precise fabrication techniques both for GNR [20] and BLG [21], it becomes important to clarify intrinsic effects of the band-gap opening on electron transport in A-GNR-FETs and BLG-FETs.…”

Top gated graphene transistors with different gate insulators

“…For this class of devices, the recently discovered new material graphene may become extremely important. Graphene exhibits properties which open new prospects to overcome the limitations of current classical silicon based devices and even of the channel replacement materials, such as germanium and III-V compounds [1][2][3]. Furthermore, this material opens new possibilities for integrated circuit design [4,5] and is promising for high frequency devices [6][7][8].…”