Self-assembled anchoring shell on NiOx nanocrystals enables efficient and stable wide-bandgap perovskite solar cells

Abstract

By replacing surface hydroxyls with bidentate carboxylate coordination, we construct a core–shell PO–NiO_x hole transport layer that exhibits elevated zeta potential and superior colloidal stability, enabling pinhole-free films. The resulting 1.68 eV wide-bandgap perovskite solar cells achieve a champion PCE of 23.4%, a four-terminal tandem efficiency of 28.2%, and significantly enhanced thermal stability.