Solar cells based on mixed organic–inorganic halide perovskites are promising photovoltaic technologies with low‐cost and fantastic power conversion efficiency (PCE). Enhancing the nucleation and regulating the crystallization rate of perovskite films and improving the bendability of brittle hybrid grains are crucial to improving the photovoltaic performance of flexible perovskite solar cells (PVSCs). Here, a simple approach is first introduced for fabricating perovskite films with full coverage and larger crystalline size by incorporating the elastomer polyurethane (PU) into the perovskite precursor solution to both retard the crystallization rate and improve the bendability. Shiny, smooth perovskite films are obtained with compact, micrometer‐sized crystalline grains that exhibit excellent photoelectric performances. The PVSCs fabricated by incorporating PU into the perovskite precursor offer an impressive PCE of 18.7% with almost no photocurrent hysteresis and excellent stability in ambient air. More importantly, the elastomer PU additive crosslinks the grain boundaries between neighboring perovskite crystals to form a PU network that effectively improves the bendability of the perovskite films.

中文翻译：

---

通过聚氨酯进行成核和结晶控制，以增强钙钛矿型太阳能电池的弯曲性能，并具有出色的器件性能

基于有机-无机卤化物钙钛矿混合体的太阳能电池是有前途的光伏技术，具有低成本和出色的功率转换效率（PCE）。增强钙钛矿薄膜的成核和调节钙钛矿薄膜的结晶速率以及提高脆性杂化晶粒的可弯曲性对于提高柔性钙钛矿太阳能电池（PVSC）的光伏性能至关重要。在此，首先引入一种简单的方法，通过将弹性体聚氨酯（PU）掺入钙钛矿前体溶液中，既可抑制结晶速度，又可改善弯曲性，从而制造出具有完全覆盖度和更大晶体尺寸的钙钛矿膜。获得了具有致密，微米级晶粒的闪亮钙钛矿薄膜，这些晶粒具有出色的光电性能。通过将PU掺入钙钛矿前体中制成的PVSC提供了令人印象深刻的18.7％的PCE，几乎没有光电流滞后，并且在环境空气中具有出色的稳定性。更重要的是，弹性体PU添加剂使相邻的钙钛矿晶体之间的晶界交联，形成有效改善钙钛矿薄膜弯曲性的PU网络。