Strain-induced electronic phase transition in phosphorene: A Green’s function study

• Published in: Chemical physics 2019-06, Vol.522, p.249-255
• Main Authors: Hien, Nguyen D., Davoudiniya, Masoumeh, Mirabbaszadeh, Kavoos, Phuong, Le T.T., Yarmohammadi, Mohsen
• Format: Article
• Language: English
• Subjects: Black phosphorus; Density of states; Electronic phase transition; Fermi energy; Strain
• ISSN: 0301-0104
• DOI: 10.1016/j.chemphys.2019.03.013

In the present paper, we study the impacts of possible uni-, bi-, and tri-axial strains on the electronic band gap of phosphorene using the density of states (DOS) quantity through the Harrison relation. To reach this goal, we use a tight-binding Hamiltonian model and the Green’s function method. The findings report that the electronic phase of phosphorene can be adjustable in the presence of strain. The band gap increases (decreases) when applying the tensile uniaxial strains along the {x,y} (z) direction, while it decreases (increases) when the compressive uniaxial ones are applied. Interestingly, due to the inherent highly anisotropic structure of phosphorene, there is a semiconductor-to-metal phase transition along the z direction as the tensile strain is increased. Furthermore, we found that among all possible configurations for uniform biaxial strains, a flat band emerges at εx=εy=-15%, which is a quite new outcome. In addition, phosphorene supports different phase transitions when the triaxial strains are applied, introducing new electro-optical features. Hence, these findings can provide insights into the future experimental research and improve the applications of phosphorene in the real industry such as field-effect transistors.