Ethylenediammonium-Based “Hollow” Pb/Sn Perovskites with Ideal Band Gap Yield Solar Cells with Higher Efficiency and Stability

material gives an optimized PCE of 17.04%. The results highlight the strong promise of 3D hollow mixed Pb/Sn perovskites in achieving ideal band gap materials with higher chemical stability and lower Pb content for high-performance single-junction solar cells or multijunction solar cells serving as bottom cells.