Improved Environmental Stability and Solar Cell Efficiency of (MA,FA)PbI3 Perovskite Using a Wide-Band-Gap 1D Thiazolium Lead Iodide Capping Layer Strategy

There is strong interest in improving the environmental stability of hybrid perovskite solar cells while maintaining high efficiency. Here, we solve this problem by using epilayers of a wide-band-gap 1D lead iodide perovskitoid structure, based on a short organic cation, namely, thiazole ammonium (TA) in the form of lead iodide (TAPbI3). The 1D capping layer serves to passivate three-dimensional (3D) perovskite films, which promotes charge transport, improves carrier lifetime, and prevents iodide ion migration of the 3D (MA,FA)­PbI3 film (MA = methylammonium, FA = formamidinium). Furthermore, the corresponding device achieved considerable efficiency and better environmental stability than the -based analogue, delivering a champion PCE value of 18.97% while retaining 92% of this efficiency under ambient conditions in air for 2 months. These findings suggest that utilization of a 1D perovskitoid is an effective strategy to improve the environmental stability of 3D-based perovskite solar cell devices maintaining at the same time their high efficiency.

提升杂化钙钛矿太阳能电池的环境稳定性并同时维持其高光电转换效率，是当前光伏领域的重要研究方向。本研究采用基于短有机阳离子噻唑铵（TA）的宽禁带一维（1D）碘化铅类钙钛矿结构外延层（分子式为TAPbI3），解决了上述问题。该一维钝化覆盖层可对三维（3D）钙钛矿薄膜实现钝化，能够促进电荷传输、延长载流子寿命，并抑制三维(MA,FA)PbI3薄膜（其中MA为甲胺基（methylammonium），FA为甲脒基（formamidinium））中的碘离子迁移。此外，制备的对应器件不仅展现出可观的光电转换效率（PCE, Power Conversion Efficiency），其环境稳定性也优于基于三维钙钛矿的同类对照器件；最优器件的光电转换效率达18.97%，且在空气环境条件下放置2个月后仍保留初始效率的92%。上述研究结果表明，采用一维类钙钛矿材料是提升基于三维钙钛矿的太阳能电池环境稳定性、同时维持其高效率的有效策略。