This could lead to promising high-speed electronics applications,
where the large leakage of the GNR SB FET is of fewer concerns . An efficient functionality of the transistor with a doped nanoribbon has been noticed in terms of on/off current ratio, intrinsic switching delay, and intrinsic cutoff frequency . Based on the presented model, comparable with the other experimental and analytical models, the on-state current of the MOSFET-like GNR FET is 1 order of magnitude higher than that of the TGN SB FET. This is because the gate voltage ahead of the source-channel flat band condition modulates both the thermal and tunnel components in the on-state of MOSFET-like GNR FET, while it modulates the tunnel barrier only of the metal Schottky-contact TGN FET that limits the on-state current. Furthermore, TGN SB FET device performance can be affected by interlayer coupling, PLX-4720 order which can be decreased by raising the interlayer distance or mismatching the A-B stacking of the graphene layers. It is also noteworthy that MOSFETs operate in the region of subthreshold (weak inversion) as the magnitude of V GS is smaller than that of the threshold voltage. In the weak inversion
mode, the subthreshold leakage current is principally as a result of carriers’ diffusion [58, 59]. The off-state Selleckchem BIBW2992 current of the transistor (I OFF) is the drain current when V GS = 0. The off-state current is affected by some parameters such as channel length, channel width, depletion width of the channel, gate oxide thickness, threshold voltage, channel-source doping Tenofovir price profiles, drain-source junction depths, supply voltage, and junction temperature . Short-channel effects are defined as the results of scaling the channel length on the subthreshold leakage current and threshold voltage. The threshold voltage is decreased by reducing the channel length and drain-source voltage [58–61]. In the subthreshold region, the gate voltage is approximately linear [58, 59]. It has been
studied that the decrease of channel length and drain-source voltage results in shifting the characteristics to the left, and it is obvious that as the channel length gets less than 10 nm, the subthreshold current increases dramatically . Based on the International Technology Roadmap for Semiconductors (ITRS) near-term guideline for low-standby-power technology, the value of the threshold voltage is close to 0.3 V . Figure 9 illustrates the subthreshold regime of TGN SB FET at different values of drain-source voltage. As shown in this figure, for lower values of drain-source voltage, the threshold voltage is decreased and meets the guidelines of ITRS. Figure 9 Subthreshold regime of TGN SB FET at different values of V DS (V) for L = 25 nm. The subthreshold slope, S (mV/decade), is evaluated by selecting two points in the subthreshold region of an I D-V GS graph as the subthreshold leakage current is adjusted by a factor of 10.