Modulating the Rectification Effect of MoTe₂ Monolayer by Substitutional Doping

Molybdenum ditelluride (MoTe2) monolayer is a member of the transition metal disulfide (TMD) family, and its excellent physical properties, such as tunable bandgap, atomical thickness of structure, and high surface-to-volume ratio, play a major role in the performance of the nanoelectronic device. Herein, the formation energies, electronic structures, and transport properties of MoTe2 monolayers doped with the elements of main group V (N, P, As, Sb, Bi) and VI (O, S, Se) are systematically investigated using density functional theory (DFT) combined with nonequilibrium Green’s function (NEGF) approach. The calculated results demonstrated that the doping of atoms in main group V causes the MoTe2 monolayer to change from a semiconductor to a metal, whereas the doping of main group VI atoms remains the semiconductor characteristics of MoTe2 monolayers. Moreover, excellent rectification behavior is found in metal-semiconductor junctions based on the doped MoTe2, and the rectification ratio (RR) can be up to
$9.3\times 10^{{5}}$
. Furthermore, the rectification behavior of a single-layer field-effect transistor (FET) based on doped MoTe2 can be modulated by the gate voltage and the configuration of the metal-semiconductor junction. These results are useful for the design of high-performance rectifier devices based on MoTe2 monolayer.