List of Articles Graphene

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  1 - Improving On-Off Current Ratio (Ion/Ioff) in Schottky-Barrier-Type Graphene Nanoribbon FETs
    Morteza Gholipour  
  Schottky-barrier-type graphene nanoribbon transistors (SB-GNRFET), despite their prominent characteristics compared to conventional transistors, have a relatively high off-current and a low Ion/Ioff ratio. In this paper, a new structure of SB-GNRFET is presented in whic More

  Schottky-barrier-type graphene nanoribbon transistors (SB-GNRFET), despite their prominent characteristics compared to conventional transistors, have a relatively high off-current and a low Ion/Ioff ratio. In this paper, a new structure of SB-GNRFET is presented in which the gate of the transistor is divided into two parts. A constant voltage is connected to the gate located on the drain side, and the gate located on the source side is the main gate of the transistor. The proposed SB-GNRFET is simulated using non-equilibrium Green functions-based numerical simulator under different geometric and physical characteristics and in biases. The simulation results show Ion/Ioff ratio improvement of up to 6.7-fold at VDS = 0.8 V. At this voltage the ratio has increased from 1.2 in the normal SB-GNRFET transistor to 8.01 in the new transistor and the off current has been reduced from 5 µA to 0.7 µA. Also at VDS = 0.6 V, as the supply voltage, the Ion/Ioff ratio increased from 3.97 to 15.8 and the off current decreased from 0.63 µA to 0.16 µA. Manuscript profile
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  2 - Graphene‑based composite membranes for nanofiltration: performances and future perspectives
  Farzad Mehrjo
  Nanofiltration is one of the most widely used membrane processes for water purification with high practical value because of a large number of chemical species that are separated through this process. Usually, for nanofiltration, high energy–con- suming operations are i More

  Nanofiltration is one of the most widely used membrane processes for water purification with high practical value because of a large number of chemical species that are separated through this process. Usually, for nanofiltration, high energy–con- suming operations are involved including the generation of enough pressure for the rejection of jumps and lower molecular weight chemicals at the surface of the membrane. Recent developments in the synthesis of nanocomposite membranes with graphene and graphene derivatives have led to an increase in energy requirements and the increase in membranes perfor- mances. In the present review, we have presented the recent advances in the field of graphene-based composite membranes for nanofiltration with applications for both types of based solvents—aqueous solutions and organic solvents. The presentation will be focused especially on the performances of membranes and applications of these materials for the rejection of salts (Na+, Mg2+), heavy metals (Li2+), and lower molecular weight organic compounds (methylene blue, Congo red, Direct Red, Methyl orange, Reactive green 13, etc.). Modern synthesis methods like interfacial polymerization for obtaining thin-film composite nanofiltration membranes are also presented. Nanofiltration is one of the most widely used membrane processes for water purification with high practical value because of a large number of chemical species that are separated through this process. Manuscript profile