SiC2/BP5: A pentagonal van der Waals heterostructure with tunable optoelectronic and mechanical properties

Abstract

The newly discovered semiconductor two-dimension (2D) materials with unique pentagon configurations of penta-SiC2 and penta-BP5 monolayers show interesting physicochemical properties. To expand the application fields of the pentagon 2D materials, we construct the SiC2/BP5 heterostructures and investigate their electronic, mechanical, optical and transport properties based on the first-principles calculations. Our results indicate that the SiC2/BP5 heterostructure and its individual components possess flexible tunability under biaxial strain. The Young’s modulus of these systems gradually decreases with the compressive (tensile) strain increasing and the penta-BP5 exhibits negative Poisson's ratio at ε ≥ 6 %. The type-II SiC2/BP5 heterostructure with an indirect bandgap (1.260 eV) shows great potential application in photoelectric devices. The tunneling probability of the heterostructure reaches 21.17 %, promoting the carrier injection efficiency in the system. Biaxial strain and external electric field enable the type-II SiC2/BP5 semiconductor to type-I or to metal. The optical properties of the SiC2/BP5 heterostructure are a fit to its monolayers. Additionally, current–voltage curve displays that the heterostructure has small current (10−3 μA) with favorable application promising in digital integrated circuits. Our work provides a theoretical guidance for the fabrication and application of novel pentagon 2D materials.