Search

Within the approach based on chemical modification of domain boundaries of polycrystalline graphene, a transistor channel is proposed for enhanced current modulation, Ion/Ioff ratio, in the 3 to 5 order of magnitude. We observed that two types of samples functionalized by N-methylpirrolidone (NMP) and weakly fluorinated graphene are able to demonstrate high current modulation. Experimentally, Ion/Ioff ~ 103 was found for NMP functionalized graphene and Ion/Ioff ~ 104–105 for weakly fluorinated graphene. Modeling of these two systems allows us to clarify the mechanism of carrier transport in the multi-barrier films of functionalized graphene films. It is shown that remarkable value for Ion/Ioff as about 106 can be observed for the films comprising graphene regions (graphene quantum dots, GQDs) with size of ~ 30–300 nm and ~ 75–100 nm fluorinated graphene barriers. Relatively high values of Ion/Ioff ~ 103–105 are also predicted for large graphene areas separated with thin (100 nm) barriers for the weakly fluorinated graphene samples. Our study paves a way towards controllable 2D transistors.

Here, we present a detailed study on low bias current-voltage (I-V) characteristic of graphene superlattice (GSL) resonant tunneling diode (RTD) with heterostructured substrate and series of grounded metallic planes placed over graphene sheet which induce periodically modulated Dirac gap and Fermi velocity barrier. We investigate the effect of GSL parameters on I-V characteristics within the Landauer-Buttiker formalism and adopted transfer matrix method. We show how the engineering these parameters results in multipeak NDR in proposed device. Moreover we provide a novel venue to control the NDR in GSL with Fermi velocity engineering. From this viewpoint we obtain multipeak NDR through miniband align in GSL. Maximum Pick to Valley ratio (PVR) up to 167 obtained for correlation velocity of 1.9 and bias voltages between 70-130 mV. Our finding in low bias regime and high PVR multipeak NDR have a considerable importance in multi-valued memory functional circuit, low power and high-speed nanoelectronic devices application., 13 pages, 5 Figures