Fig. 4: Device performance of all-perovskite tandem solar cells and modules.

a Cross-section SEM image of all-perovskite TSCs with BDA-EDAI2 modification. b The PV parameters statistic of control and BDA-EDAI2 modified tandem devices. c J–V curves of the best-performing all-perovskite TSCs with an active area of 0.0871 cm2. d EQE spectra of the corresponding TSCs. e J–V curves of the tandem module with an aperture area of 11.3 cm2. f MPPT of small-area tandem device with encapsulation under continuous 1 sun illumination.