Quantum Dots Supply Bulk- and Surface-Passivation Agents for Efficient and Stable Perovskite Solar Cells

Summary Defect passivation and surface modification of hybrid perovskitefilms are essential to achieving high power conversion efficiency (PCE) and stable perovskitephotovoltaics. Here, we demonstrate a facile strategy that combines high PCE with high stability in CH 3 NH 3 PbI 3 (MAPbI 3 ) solar cells. The strategy utilizes inorganic perovskitequantum dots (QDs) to distribute elemental dopants uniformly across the MAPbI 3 film and attach ligands to the film’s surface. Compared with pristine MAPbI 3 films, MAPbI 3 films processed with QDs show a reduction in tail states, smaller trap-state density, and an increase in carrier recombination lifetime. This strategy results in reduced voltage losses and an improvement in PCE from 18.3% to 21.5%, which is among the highest efficiencies for MAPbI 3 devices. Ligands introduced with the aid of the QDs render the perovskitefilm’s surface hydrophobic—inhibiting moisture penetration. The devices maintain 80% of their initial PCE under 1-sun continuous illumination for 500 h and show improved thermal stability.