From this result we conclude that Ni 2+ and Pb 2+ mixtures do not mix uniformly at the nominal concentrations that we prepared. This may indicate that Ni 2+ is not incorporated into the 3D structure. However, lack of diffraction peaks corresponding to unconverted NiI2 and low dimensional perovskite, as well as the orientational influence of Ni 2+ in these compositions, suggests that it does influence the overall structure of the bulk material. Another possibility is that Ni 2+ is not incorporated into the B site of the ABX3 perovskite structure when high nominal doping ), extrapolated from a Tauc plot (Figure ). We note that the observed band gaps appear to be independent of Ni 2+ concentration, which is another indicator that the Ni 2+ may not be incorporating into the B site of the material, since the band edge is primarily derived from the metal and halide orbitals of the BX6 octehedra. In the visible region, the incorporation of Ni 2+ produces two broad absorption features between 3.0 -3.75 eV, which are not observed in pristine MAPbI3 (Figure ). Interestingly, the increased absorption coefficients in the visible range would be favorable for a solar cell device. However, we also report strong emission quenching in these samples with the addition of any amount of Ni 2+