(Figure ). We hypothesize that Ni 2+ may act as a recombination center in devices due to the presence of low-lying ligand field states that introduce non-radiative recombination pathways for the excitonic excited state. The lowest lying ligand field state in NiI2 single crystals occurs in the near-IR region at ~0.9 eV, which supports the hypothesis that lower lying orbitals in Ni could provide sub gap states. This observation is additionally consistent with theoretical calculations for MA(Pb1-xNixBr3) which show that partial Ni 2+ substitution leads to new mid-gap states. Reported MAPbI3 solar cell devices doped with 10% Ni 2+ show a significant reduction in current density, which is consistent with trap states inducing non-radiative recombination of charge carriers. These results are not consistent with what has been observed