Modulation of interfacial electronic properties in PbI₂ and BN van der Waals heterobilayer via external electric field

Highlights: • An atomically type-II heterobilayer which is suitable for optoelectronics and solar cell with wide bandgap was formed. • The charge redistribution is mainly on the surface and the amount of electrons depends on the strength of E_field. • The bandgaps varying with E_field can be divided into three ranges indicating different E_field-sensitive which may possess potential in sensor. • Increasing the E_field upon 0.07 V/Å, the band alignment converts from type-II to type-I heterojunction. - Abstract: The interfacial electronic properties of PbI₂ and BN van der Waals (vdW) heterobilayer are explored by using density functional theory (DFT) method. An intrinsic type-II heterostructure with a wide bandgap is demonstrated. The spatial separation of the lowest energy electron-hole pairs can be actualised and make PbI₂/BN heterostructure as a good candidate for applications in optoelectronics and solar cell. A simulation of E_field is actualized to modify its electronic properties. Band alignment converts from type-II to type-I heterostructure separated by a forward voltage with the value of about 0.07 V/Å. Three regions implying different E_field-sensitive properties are obtained from the variations of bandgap with E_field. The charge redistribution with an E_field is mainly on the surface of PbI₂ and BN layers as well as the amount of electrons depends on the strength of E_field. In addition, the PbI₂/BN heterobilayer exhibits more outstanding optical conductivity capability. Our results could bring forward a new perspective on sensor and shed light on the design of novel nano- and optoelectronics based on the PbI₂/BN vdW heterostructure.