Coulomb drag by injected ballistic carriers in graphene n${}^{+}$-i-n-n${}^{+}$ structures. Doping and temperature effects

The Coulomb carrier drag effect in lateral n${}^{+}$-i-n-n${}^{+}$ graphene diodes and field-effect transistors with the injection of ballistic electrons into the n-region are evaluated. Calculating the drag factor determining the amplification of the injected current, its dependence on the structural parameters, carrier Fermi energy in the n-region, and temperature is found. As demonstrated, the drag factor exhibits a maximum in certain values of the Fermi energy (i.e., the gate voltage and density of the remote donors) and the temperature. The parameter determining the shape of the current-voltage characteristics (monotonous or S shaped) is also calculated. The obtained results can be used for the optimization of the structures under consideration for different devices, in particular, voltage- and current-driven switches, frequency multipliers, and terahertz emitters. (© 2021 Wiley‐VCH GmbH)