Fig. 1. Schematic diagram of the device structure of MA₃Sb₂I₉ perovskite photodetector

Fig. 2. SEM images of MA₃Sb₂I₉ perovskite thin films treated by MACl solution with different concentrations

Fig. 3. (a) UV-vis spectra and (b) XRD patterns of the MA₃Sb₂I₉ perovskite thin films before and after the MACl treatment

Fig. 4. (a) XPS measurement full spectrum; high-resolution spectrum of (b) Cl 2p (c) Sb 3d (d) I 3d of perovskite thin films before and after MACl treatment with different concentrations

Fig. 5. (a) Steady-state PL and (b) TRPL spectrum of MA₃Sb₂I₉ perovskite thin films before and after MACl treatment with different concentrations

Fig. 6. Water contact angle of MA₃Sb₂I₉ perovskite thin films before and after MACl treatment

Fig. 7. (a) Dark-state I-V curves of MA₃Sb₂I₉ perovskite photodetectors treated by MACl with different concentrations; (b) light and dark-state I-V curves under untreated and optimal conditions

Fig. 8. (a) J_sc distribution, (b) EQE, (c) R, (d) D^* of the MA₃Sb₂I₉ perovskite photodetector

Fig. 9. Single-cycle ON/OFF response of (a) without post-treatment and (b) with 4 mg/mL MACl post-treatment; (c) multi-cycle ON/OFF response