Theoretical study of methyl-ammonium lead iodide perovskite’s response under tensile/compressive loads

In the present work, we will utilize all atom-molecular dynamics simulations to study mechanical behavior of methyl-ammonium lead iodide (MAPbI3) perovskites when subjected to mechanical loads. Uniaxial tension and compression tests in X, Y and Z directions are simulated at ambient conditions. Plotting variations of stress components with the applied strain, the yield and ultimate strengths of MAPbI3 perovskite are obtained where Poisson’s ratios in all directions are computed directly from these simulations. Introducing a straightforward approach, all the stiffness matrix’s elements are computed. It is shown that compressive strength of MAPbI3 perovskite is much higher than its tensile counterpart which represents tension–compression asymmetry in MAPbI3 perovskites. Moreover, Mohr–Coulomb failure criterion is employed to describe failure of MAPbI3 perovskites. To validate applicability of Coulomb–Mohr criterion in describing failure of MAPbI3 perovskite, it is simulated under a different loading scenario which then failure is evaluated using Coulomb–Mohr criterion.