The strain effect on superconductivity in phosphorene: A first-principles prediction

The effects of biaxial and uniaxial strains on electron-phonon coupling and superconductivity in monolayer phosphorene are systematically investigated by first-principles calculations. It is found that the electron-phonon coupling primarily comes from the low frequency optical phonon modes aroundB3g 1 , and the biaxial strain gives rise to more a obvious increase in density of states around the Fermi level and phonon softening in the low frequency regime compared to the other two types of uniaxial strain. Therefore, the electron-phonon coupling is more significantly enhanced by the biaxial strain than the uniaxial strains and the superconducting transition temperature Tc increases sharply from 3 Kto 16 Kat the typical doping concentration n_2D = 3.0 × 10¹⁴cm^-2 when the biaxial strain reaches 4.0%.