Fig. 3: Photovoltaic performance and stability.

a J–V curves of the best-performing PSCs with the control PVK, PVK/MBAPbI3 and PVK/MVPb2I6. b J–V curves of the best-performing PVK/MVPb2I6 PSCs with forward and reverse scans. c EQE curves and integrated JSC of the PVK/MVPb2I6 PSC. d Statistics of the PCEs among 15 individual devices with different heterostructures. e Stabilized current and efficiency output under continuous illumination. f ISOS-L-1I stability of the encapsulated devices measured at MPP under continuous AM 1.5 G simulated solar illumination at room temperature in N2. g ISOS-D-1 stability of the unencapsulated device measured at room temperature and 20–40% relative humidity. Error bar represents the confidence interval of each stability. Source data are provided as a Source Data file.