First principles calculation of metal (Ni and Cu) contact on the electronic transport properties of 2D GeP semiconductor

Two-dimensional (2D) IV-V semiconductors are shown to possess suitable bandgap, strongly anisotropic electronic and optical properties for nanoelectronic and optoelectronic applications. Motivated by the experimental demonstration of the 2D IV-V semiconductors, we have computationally designed the monolayered GeP nanodevice consisting of nickel (Ni) and copper (Cu) metal contacts, and evaluated their transport properties. Using first principles calculations combined with non-equilibrium Green’s function, we have calculated the current density (J) versus bias (Vb), and the transmission coefficient. Both Ni and Cu metals could form excellent metallization contact with the GeP semiconductor channel, leading to effective carrier injection to the semiconductor and yielding significant improvements on the transport properties. The current is determined by the potential difference at the interface and the left/right electrode density of states (L/RDOS) coupling of the device. These two factors play predominant role at low and moderate biases, respectively. Our simulations have shown that the 2D GeP electronic device could be significantly improved by appropriate metal contact, which can be helpful to the 2D IV-V semiconductors for future electronic applications.