Antimony Potassium Tartrate Stabilizes Wide-Bandgap Perovskites for Inverted 4-T All-Perovskite Tandem Solar Cells with Efficiencies over 26%

Highlights A versatile material-antimony potassium tartrate is added to wide-bandgap perovskite cells for the first time. Inverted wide-bandgap perovskite solar cells with a structure of ITO/MeO-2PACz/perovskite/C 60 /ALD-SnO 2 /Cu yield a champion power conversion efficiency of 20.35%. A perovskite/perovskite four-terminal tandem solar cell with efficiency of 26.3% is achieved.