So far, it’s been widely acknowledged that the PbI₂ decomposition under illumination mainly accounts for the degradation of perovskite solar cells (PSCs) under maximum power point (MPP) tracking condition. However, PSCs without excess PbI₂ were also reported to deteriorate rapidly under the same condition. Here, we demonstrate that the key to enhance PSCs stability under MPP tracking condition is not to have fascinating surface morphology with effective suppression of nonradiative recombination traps but to prevent the migration of iodine ion (I⁻) under light illumination. By partially substituting methylammonium chloride (MACl) with methylammonium iodide (MAI) and simutaneouly introducing I₂ during the sequential deposition, the iodine vacancies in perovskite films are substantially suppressed, thereby limiting the pathways for I⁻ migration. As a consequence, PSCs with efficiency of 24.28% are fabricated with remarkably enhanced working stability.

到目前为止，人们普遍认为，光照下的 PbI ₂分解主要解释了钙钛矿太阳能电池（PSC）在最大功率点（MPP）跟踪条件下的退化。然而，据报道，没有过量 PbI ₂的 PSC 在相同条件下也会迅速恶化。在这里，我们证明了在 MPP 跟踪条件下增强 PSCs 稳定性的关键不是具有迷人的表面形态和有效抑制非辐射复合陷阱，而是防止碘离子 (I ^- ) 在光照下的迁移。通过用甲基碘化铵 (MAI) 部分取代甲基氯化铵 (MACl) 并同时引入 I ₂在连续沉积过程中，钙钛矿薄膜中的碘空位被大大抑制，从而限制了 I ^-迁移的途径。因此，制造效率为 24.28% 的 PSC 具有显着增强的工作稳定性。