Tandem Solar Cells As a more efficient alternative to the crystalline Si solar cell, the perovskite/Si tandem solar cell is attracting attention. In article 2201006, Ki Hong Kim, Jin Young Kim, and co-workers summarize the progress of the PVSK/Si tandem solar cell depending on the types of Si bottom cells: passivated emitter rear contact, heterojunction with intrinsic thin layer, and polysilicon-passivated contact.