CsPbCl3‐Cluster‐Widened Bandgap and Inhibited Phase Segregation in a Wide‐Bandgap Perovskite and its Application to NiOx‐Based Perovskite/Silicon Tandem Solar Cells

of 1.93 V and a final efficiency of 25.5%. These findings provide critical insight into the fabrication of highly efficient and stable wide-bandgap perovskites.