Figure 5

XRD of aged PSCs stored in ambient condition over 10 days in a petri dish without encapsulation at 25 °C and RH ~ 30 to 40%. XRD spectra of: (a) triple cation with Au; (b) triple cation with Ag; (c) MAPbI₃ with Au; (d) MAPbI₃ with Ag. Asterisks in (b) and (d) indicate the diffractions at 2θ = 22.3°, 23.8°, and 39.2° corresponding to the (100), (002), and (111) peaks of β-AgI, respectively. These peaks indicate the rapid formation of AgI in Ag based PSCs, while in (a,c), the formation of AuI is almost negligible since the characteristic AuI diffraction peaks were absent from our spectra, as noted in the Supporting Information of Ref.³⁰.