Figure 1.

(i) Schematic of the fabrication process for perovskite solar cell. (a) Step 1: FTO Substrate is cleaned with different solvents. (b) Step 2: SrFe₂O₄ is spin-coated in ambient air. The fabrication process is shifted to the glove box. (c) Step 3: the CH₃NH₃PbI₃ is coated onto the SrFe₂O₄ layer. (d) Step 4: ZnO is spin-coated over the perovskite absorber layer. (e) Step 5: Pt electrode is sputtered on the top of the device. (ii) Schematics of a three-step process for the fabrication of the CH₃NH₃PbI₃ layer. Process 1 involved the preparation of PbI₂ sol. Process 2 involved the preparation of CH₃NH₃I sol. Process 3 involved the formation of the CH₃NH₃PbI₃ layer by spin coating technique onto FTO.