fig3

Figure 3. (A) An unprocessed TA MAPbI₃ SEM image; (B) depicts the ASTM E112-13 line method for grain size determination; (C) shows masks for each grain generated by the AI segmentation model in the image; (D) The average grain diameters calculated using the AI segmentation model for the four types of MAPbI₃. The scale bar in (A)-(C) is 100 nm. TA: Thermal annealed; MAPbI₃: Methylammonium lead iodide; SEM: Scanning electron microscope; AI: Artificial intelligence.