SEM images showing the TiO2 nanostructures with the PbI2 pre-coating and MAPbI3(Cl) infiltration into the PS-templated TiO2. Figure S2. The effect of PS ratio and the concentration of precursor solution on the X-ray diffraction of MAPbI3(Cl) perovskite. Figure S3. Cross-sectional back scattered electron images exhibiting the MAPbI3(Cl) perovskite infiltration in the porous TiO2 layer. Figure S4. Cross-sectional elemental distributions from energy dispersive X-ray spectroscopy (SEM-EDS) showing the Sn, Ti, O, Pb, and I distributions for different porous TiO2 scaffolds. Figure S5. Microstructures of MAPbI3(Cl) on the TiO2 blocking layer. Figure S6. Photovoltaic parameters with the average and the standard deviation in each condition. Figure S7. Ideal one-diode model for the perovskite solar cell. Figure S8. Current density vs. bias under dark and the corresponding fitting results. Figure S9. The effect of TiO2 blocking layer by sputter deposition on the performance of the perovskite solar cell. Figure S10. Morphology comparison by the spin-coating and sputter deposition
