Modulating defects in metal halide perovskites using lattice strain

Defects play a pivotal role in controlling the performance of metal halide perovskite solar cells. Of all point defects in the prototypical methylammonium lead iodide perovskite, iodine interstitials have been identified as the main source of non-radiative recombination, leading to a loss of power conversion efficiency. In this work, we use first-principles calculations to investigate the modulation of defect properties, such as transition levels by the application of isotropic and epitaxial lattice strain. We also compare the properties of defects obtained using exchange-correlation functionals at the generalized gradient approximation and the hybrid level.