Performance Limits Projection of Black Phosphorous Field-Effect Transistors

Ballistic device performance of monolayer black phosphorous (BP) field-effect transistors (FETs) is investigated in this letter. Due to the anisotropic effect mass of the carriers, the ON-state current is dependent on the transport direction. The effective masses are lower in the armchair direction, which provides higher drive current at the same biasing. The degree of anisotropy is higher for the holes, which improves the performance of p-type devices. The intrinsic delay of 20-nm BP FETs is in the range of 50 fs at ON-/OFF-current ratio of four orders. Monolayer BP FETs outperform both MoS2and Si FETs for both nand p-type devices in terms of ballistic performance limits, due to highly anisotropic band structure.