Fig. 6

a, c μ-PL intensity and b, d spectral position of the PL peak for the layout of TCO/bl-TiO₂/mp-TiO₂/MAPbI₃ with 0.032 M and 0.044 M MAI concentration. High resolution μ-PL imaging overlaid with SEM images acquired on the same spot. Note the different color bars in b, d which is 766–774 nm for the 0.032 M sample and has a much smaller range (764–766 nm) for the 0.044 M sample. The scale bar is 3 μm for the 0.032 M film and 2 μm for 0.044 M. Reprinted with permission from Ref. [36]