Significant band gap induced by uniaxial strain in graphene/blue phosphorene bilayer

Abstract

The effect of in-plane uniaxial strain on band structures and electronic properties of graphene/blue phosphorene (Gr/BPh) bilayer has been investigated by using first-principles calculations. The results show that the intrinsic electronic properties of graphene and blue phosphorene are preserved well in the unstrained bilayer. Upon the application of in-plane uniaxial strain, the band gap of the Gr/BPh bilayer can be easily opened by ∼120 meV near ±2%, and the value of band gap increases with increasing the strain value. A maximum gap value ∼240 meV is obtained around ±4% strain. By analyzing the projected density of states and charge density differences, we reveal that the opened band gap under strain is closely related to the change in electronic structure of Gr/BPh bilayer, which is greatly influenced by the electron redistribution between graphene and BPh layers as well as the orbital hybridizations between carbon and phosphorus atoms. Further study finds that the band gap can not be opened when the in-plane biaxial strain is applied to the Gr/BPh bilayer. The present work provides us an effective avenue to tune the electronic structures and band gap for Gr/BPh bilayer.