Effect of external electric field on the electronic structure of MoSe₂/Arsenene heterojunction

In this paper, the effects of the thermostability, band structure, and the external electric field on the electronic structure of MoSe2/Arsenene heterojunction are calculated based on the density functional theory. The calculation results show that the MoSe2/Arsenene heterojunction is a type-II heterojunction with a bandgap of 0.89 eV. When MoSe2 and arsenene combine by van der Waals force, the electrons are transferred from MoSe2 to arsenene, the holes are transferred from arsenene to MoSe2, with the direction of the internal electric field from MoSe2 to arsenene. The MoSe2/Arsenene heterojunction with valence band top and conduction band bottom contributed by arsenene and MoSe2, respectively, shows excellent thermostability at room temperature. The external electric field can effectively modulate the electronic structure of heterojunction. When the electric field is negative, electrons are transferred from MoSe2 to arsenene and holes from arsenene to MoSe2. The Fermi level of arsenene moves down while that of MoSe2 moves up. When the electric field is positive, the direction of electron and hole transfer are opposite to that when the electric field is negative. The Fermi energy level of arsenene and MoSe2 also move in the opposite direction.