Excess PbI₂ has been widely introduced in halide perovskite precursor solution to passivate the grain boundary defects in high efficient perovskite solar cells (PSCs). However, the passivation effect is highly sensitive to the PbI₂ content and overmuch PbI₂ affects the crystalline growth and charge transport. We report here a precious control of excess PbI₂ into perovskite grain boundaries by methylamine treatment for efficacious defects passivation and charge extraction. The crystallization of the deposited perovskite films was carefully evaluated and the charge recombination dynamics were systematically analyzed through time-resolved photoluminescence spectroscopy, space charge limited current, electrochemical impedance spectroscopy and Mott-Schottky analysis. The precise PbI₂ introduction to the grain boundaries results in a significantly lower defect state density, efficient charge extraction and prolonged carrier lifetime, causing a notable increase of short-circuit current density and negligible hysteresis in the corresponding device. Our work demonstrates a reliable method to alleviate the rigorous tolerance of PbI₂ excess in high efficient PSCs.

过量的PbI ₂已广泛引入卤化物钙钛矿前体溶液中，以钝化高效钙钛矿太阳能电池（PSC）中的晶界缺陷。但是，钝化效应对PbI ₂含量高度敏感，过多的PbI ₂影响晶体生长和电荷传输。我们在这里报告了对过量PbI ₂的宝贵控制通过甲胺处理进入钙钛矿晶界，进行有效的钝化和电荷提取。仔细评估沉积的钙钛矿薄膜的结晶，并通过时间分辨光致发光光谱，空间电荷限制电流，电化学阻抗光谱和莫特-肖特基分析系统地分析电荷复合动力学。精确地将PbI ₂引入晶界可显着降低缺陷态密度，有效地进行电荷提取并延长载流子寿命，从而导致相应器件中的短路电流密度显着增加且滞后现象可忽略不计。我们的工作证明了减轻PbI ₂严格耐受性的可靠方法 高效PSC中的过量。