Enhanced Uniformity and Stability of Pb-Sn Perovskite Solar Cells via Me4NBr Passivation

摘要

Tin-lead (Sn-Pb) based hybrid perovskite solar cell is investigated as a potential solution to extend the light absorption spectrum range, and to reduce environmental hazard caused by lead in the perovskite materials. Nonetheless, due to the instability of tin, the Sn-Pb based perovskite solar cells suffer from more severe efficiency degradation when compared to the lead-based perovskite solar cells, which restricts its further development. Here, a quaternary ammonium halide compound, Me4NBr, is introduced to passivate the Sn-Pb based perovskite surface. The Me4NBr effectively reduces the surface defects and enhances the open circuit voltage and fill factor of the Sn-Pb based perovskite solar cell. Moreover, the Me4NBr treated Sn-Pb perovskite cells also demonstrate a significant stability enhancement when compared with the untreated Sn-Pb perovskite cells.