Engineering of the electronic structure of Fe-adsorbed black phosphorus monolayer by strain

Abstract Metal atom adsorption is recently considered to be an efficient approach to achieve stability of black phosphorus required by practical devices with no damage to its pristine excellent properties. Using first-principles calculations, we studied the structures and electronic properties of monolayer black phosphorus with Fe atom adsorption under different biaxial strain. Monolayer BP becomes an indirect bandgap semiconductor due to the contribution of adsorbed Fe atom. Strain is considered as a promising way to turn the electronic structures of the adsorption systems. The compressive strain reduces the band gap value of the systems, and eventually results in a semiconductor-metal transition when the strain reaches -8 %. The tensile strain would turn the value of band gap ranging from 0.96 eV to 0.60 eV, and an indirect-direct band gap transition would occur with the tensile strain of 4 %. In addition, it is found that the charge density difference and charge transfer nearly unchanged under different strain, means that the Fe-P covalent bonds are very strong. The combination of adjustable electronic properties with stability makes black phosphorus an attractive material for fundamental physics studies.