Band structure and Schottky barrier modulation in multilayer black phosphorene and black phosphorene/graphene heterostructure through out-of-plane strain

摘要

Density functional theory is utilized to investigate the electrical properties of multilayer black phosphorene and phosphorene/graphene heterostructure under out-of-plane strain. The effects of the number of layers and stacking order of layers on the band structure are studied. The band gap of phosphorene is inversely proportional to the number of layers, varying from 0.93 eV for single-layer to 0.15 eV for five-layer phosphorene. The results show that the direct band gap of phosphorene changes to indirect and a semiconductor to metal transition occurs in critical out-of-plane compressive strain level of 10.5%, 11% and 9% for AA, AB and AC stacked bilayer phosphorene, respectively. The critical strain depends on the band gap value and is reduced in multilayer structures. The heterostructure exhibits the characteristics of a p-type Schottky barrier which strongly depends on the strain. The p-type to n-type Schottky barrier transition occurs at the out-of-plane tensile strain of 8.5%.