The partial replacement of the A-site by divalent methylenediammonium cations inhibits ion migration and photoinduced halide segregation in wide-bandgap perovskites. Single-junction devices achieve a certified power conversion efficiency of 22.71%, whereas perovskite/Cu(In,Ga)Se2 tandem devices exhibit an efficiency of 30.13% in a four-terminal architecture.
- Liuwen Tian
- Enbing Bi
- Rui Wang