Inorganic nanoparticles (NPs) are promising materials widely used in the transport layer of perovskite solar cells. However, the tendency of inorganic NPs to aggregate hinders their further application in preparing large-area films. The aggregation of inorganic NPs worsens the coffee ring effect, leading to the formation of inhomogeneous films. Consequently, the poor contact of bottom interface of the films affects the crystallization of the perovskite films, degrading the overall device performance. Herein, an electrically charged polymer, polyethyleneimine (PEI), was introduced into an inorganic NP solution. The charged nature of PEI significantly inhibited the aggregation of inorganic NPs. Moreover, the addition of PEI increased the viscosity of the inorganic NP solution, thereby reducing the coffee ring effect observed in the films. We achieved a power conversion efficiency of 23.2% based on a 1-cm² normal perovskite solar cell (N-I-P device) with a SnO₂ transport layer. The efficiency of the 1-cm² inverted PSCs (P-I-N device) with a NiO_x-based structure was improved to over 20%, demonstrating the universality of this strategy.

无机纳米颗粒作为一种极具前景的材料, 在钙钛矿太阳电池的传输层中得到了广泛应用. 然而, 无机纳米颗粒易于聚集的特性阻碍了其进一步的发展. 在大面积制备过程中, 无机纳米颗粒的聚集加剧了“咖啡环效应”, 导致薄膜不均匀, 使得底部界面性能较差, 进而影响钙钛矿薄膜的结晶, 最终导致整个器件性能下降. 为解决这一问题, 我们将一种带电聚合物––聚乙烯亚胺引入至无机纳米颗粒溶液中. 聚乙烯亚胺的带电性质对无机纳米颗粒的聚集起到了显著的抑制作用, 此外, 添加聚乙烯亚胺还增加了无机纳米颗粒溶液的粘度, 有助于减少薄膜上的负面咖啡环效应. 最终, 我们在基于1-cm²正式结构且使用SnO₂传输层的器件上实现了23.2%的光电转换效率. 为进一步证明这一策略的普适性, 我们还将此策略验证基于NiO_x传输层的1-cm²反式器件, 其转换效率超过20%