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

Abstract

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.

Recent Progresses on Defect Passivation toward Efficient Perovskite Solar Cells

“…Wu et al ingeniously applied organic donor–π–acceptor (D–π–A) molecules with different electron density distributions to the passivation project, and the excellent passivation for lead ion defects of them increased the V OC by 0.08 V (Figure e) . There are many other passivation cases that use similar principles, such as IT‐4F, Me 4 NBr and the alkylammonium halogen salt mentioned in Section . Integrated passivation of zwitterion or polyfunctional groups will be one of the future development directions.…”

“…[89] There are many other passivation cases that use similar principles, such as IT-4F, [90] Me 4 NBr and the alkylammonium halogen salt mentioned in Section 3.2.2. [91] Integrated passivation www.advancedsciencenews.com Adv. Energy Mater.…”

Strategies for Improving the Stability of Tin‐Based Perovskite (ASnX3) Solar Cells

“…In 2019, Du et al, introduced Me 4 NBr to passivate the Sn‐Pb‐based perovskite surface and improved stability. [ 80 ]…”

Investigation of the S-Shaped Current–Voltage Curve in High Open-Circuit Voltage Ruddlesden–Popper Perovskite Solar Cells

“…To further the investigation, dark current density-voltage (J-V) characteristics of different HTL devices before and after ageing was performed, as shown in Supplementary Figure S2. The significant reduction of the leakage current for all samples after ageing is an indication of suppression of carrier recombination (Du et al, 2019).…”