Adjusting Schottky barrier height and enhancing diode performances in 1T-MoT2/WSeTe (MoSeTe) heterojunctions by interlayer flipping

Two-dimensional (2D) Janus materials have received significant attention due to their unique physical structure and superior electronic and optical properties. Here, we investigate the diode performance of 2D Janus WSeTe or MoSeTe vertical contact with 2D 1T-MoTe2 using ab initio quantum transport simulations. When the Te atomic layer of WSeTe or MoSeTe contacts with 1T-MoTe2 (known as type-A heterojunction), the contact interface exhibits significant Fermi level pinning (FLP), resulting in a larger Schottky barrier height (SBH). Through interlayer flipping, the Se atomic layer of WSeTe or MoSeTe comes into contact with 1T-MoTe2 (known as type-B heterojunction), FLP at the contact interface will be significantly suppressed, resulting in obvious reduction of the SBH. Therefore, Schottky diodes based on type-B heterojunction exhibit superior performances with higher rectification ratio and larger photocurrent compared to Schottky diodes based on type-A heterojunction.