Thin films of perovskite deposited from solution inevitably introduce large number of defects, which serve as recombination centers and are detrimental for solar cell performance. Although many small molecules and polymers have been delicately designed to migrate defects of perovskite films, exploiting credible passivation agents based on natural materials would offer an alternative approach. Here, an eco-friendly and cost-effective biomaterial, ploy-l-lysine (PLL), is identified to effectively passivate the defects of perovskite films prepared by blade-coating. It is found that incorporation of a small amount (2.5 mg mL⁻¹) of PLL significantly boosts the performance of printed devices, yielding a high efficiency of 19.45% with an increase in open-circuit voltage by up to 100 mV. Density functional theory calculations combined with X-ray photoelectron spectroscopy reveal that the functional groups (NH₂, COOH) of PLL effectively migrate the Pb-I antisite defects via Pb-N coordination and suppress the formation of metallic Pb in the blade-coated perovskite film. This work suggests a viable avenue to exploit passivation agents from natural materials for preparation of high-quality perovskite layers for optoelectronic applications.

从溶液中沉积的钙钛矿薄膜不可避免地会引入大量的缺陷，这些缺陷会成为复合中心，并不利于太阳能电池的性能。尽管已经精心设计了许多小分子和聚合物来迁移钙钛矿薄膜的缺陷，但开发基于天然材料的可靠钝化剂将提供另一种方法。这里，环境友好的和具有成本效益的生物材料，ploy-升赖氨酸（PLL），被识别为有效地钝化由刮涂制备钙钛矿薄膜的缺陷。发现掺入少量（2.5 mg mL ^-1PLL的性能大大提高了印刷设备的性能，开路电压提高了100 mV，产生了19.45％的高效率。密度泛函理论计算结合X射线光电子能谱揭示了PLL的官能团（NH ₂，COOH）通过Pb-N配位有效地迁移了Pb-I反位缺陷，并抑制了叶片包覆钙钛矿中金属Pb的形成。电影。这项工作为利用天然材料的钝化剂制备用于光电应用的高质量钙钛矿层提供了一条可行的途径。