Fig. 1. (Color online) Schematic diagram of (a) the MAPbI₃ perovskite fabrication treated by MAI healing method and (b) MAI healing process.

Fig. 2. (Color online) SEM images of MAPbI₃ perovskite treated by MAI healing method with heating temperature of (a) 100 °C, (b) 120 °C, (c) 130 °C and (d) 150 °C. (e) Comparison of grain size of the MAPbI₃ film with different heating temperature. (The processing time was set as 10 min.)

Fig. 3. (Color online) SEM images of MAPbI₃ perovskite treated by MAI healing method with processing time of (a) 12 min (low magnification), (b) 12 min (high magnification), (c) 15 min and (d) 18 min. (e) Comparison of grain size of the MAPbI₃ film with different processing time. (The heating temperature was set as 100 °C.)

Fig. 4. (Color online) SEM and AFM images of MAPbI₃ perovskite films treated by (a, c, d) post-annealing, (b, e, f) MAI healing. (g) Statistics of the average grain size and (h) grain boundary density of MAPbI₃ perovskite film with different treatment.

Fig. 5. (Color online) Phase structure of MAPbI₃ films with different treatments. (a) XRD patterns. (b) Partial enlarged views.

Fig. 6. (Color online) Optical and electrical spectra of MAPbI₃ films with different treatments. (a) UV–vis spectra of MAPbI₃ film with different treatments. (b) UV–vis spectra of MAPbI₃ film treated by MAI healing as-prepared and after storage in ambient air (relative humidity: 30%–40%) for 10 days. (c) PL and (d) TRPL spectra of MAPbI₃ films with different treatment.

Fig. 7. (Color online) (a) Cross section SEM image of the PSCs treated by MAI healing. (b) J–V curves of the best performing device of MAPbI₃ absorber with different treatment. (c) Photovoltaic performance of PSCs with different treatment as-prepared and after storage in ambient air (relative humidity: 30%–40%) for 192 h.

Table 1. Statistic results of the photovoltaic performance of the PSCs prepared with different method.